Number of results: 2,253
calculus
Well, we know x=3 and y=8 and dx/dt=4. We need to find z (the distance from the particle to the origin) dy/dt, and finally our answer dz/dt. First solve for dy/dt y=2(3x+7)^(1/2) dy/dt=[2(1/2)(3x+7)^(-1/2)](3dx/dt) dy/dt=[(3x+7)^(-1/2)]3dx/dt dy/dt=[(3(3)+7)^(-1/2)](3(4)) dy/...
Tuesday, October 26, 2010 at 6:52am by Stephanie
calculus
xdy/dt + ydx/dt - 5dx/dt + 6x^2dx/dt = 0 2dy/dt - 2(-5) - 5(-5) + 6(25)(-5) = 0 solve for dy/dt
Sunday, February 24, 2008 at 10:18pm by Reiny
calculus
s^2 = 3^2 + 4^2 - 2(3)(4)cos T 2s ds/dt = 24sin T dT/dt s ds/dt = -12sin T dT/dt when T = 90°, s = 5, sinT = 1 , dT/dt = 2 rad/sec 5 ds/dt = -12(1)(2) ds/dt = -24/5 = -4.8 inches/sec at that precise instant, the third side is decreasing at 4.8 inches/sec
Saturday, March 5, 2011 at 4:35pm by Reiny
differentiate
A = 1/2 ab Sinè How is dA/dt related to da/dt, db/dt and dè/dt dA/dt= 1/2 b SinTheta da/dt + 1/2 a SinTheta db/dt + 1/2 ab cosTheta dTheta/dt This is a U = xyz form dU/dt= xy dz/dt + ...
Saturday, December 9, 2006 at 1:14pm by Jen
chemistry
well yea, but the only responses listed are as follows: -d(Cl2)/dt = 2[-d(F2)/dt] -d(Cl2)/dt = 3[-d(F2)/dt] 2[-d(Cl2)/dt] = -d(F2)/dt 3[-d(Cl2)/dt] = -d(F2)/dt -d(Cl2)/dt = -d(F2)/dt and none of those make sense.
Friday, May 29, 2009 at 7:33am by uci student
chemistry(check my answer)
Which equation describes the relationship between the rates at which Cl2 and F2 are consumed in the following reaction? Cl2(g) + 3F2(g) yield 2ClF3(g) a)-d(Cl2)/dt = -d(F2)/dt b)-d(Cl2)/dt = 2[-d(F2)/dt] c)3[-d(Cl2)/dt] = -d(F2)/dt d)2[-d(Cl2)/dt] = -d(F2)/dt e)-d(Cl2)/dt = 3...
Friday, May 14, 2010 at 2:27am by eng
chemistry
Which equation describes the relationship between the rates at which Cl2 and F2 are consumed in the following reaction? Cl2(g) + 3F2(g) yield 2ClF3(g) a)-d(Cl2)/dt = -d(F2)/dt b)-d(Cl2)/dt = 2[-d(F2)/dt] c)3[-d(Cl2)/dt] = -d(F2)/dt d)2[-d(Cl2)/dt] = -d(F2)/dt e)-d(Cl2)/dt = 3...
Friday, May 14, 2010 at 11:06pm by eng
chemistry(check my answer)
Which equation describes the relationship between the rates at which Cl2 and F2 are consumed in the following reaction? a)-d(Cl2)/dt = -d(F2)/dt b)-d(Cl2)/dt = 2[-d(F2)/dt] c)3[-d(Cl2)/dt] = -d(F2)/dt d)2[-d(Cl2)/dt] = -d(F2)/dt e)-d(Cl2)/dt = 3[-d(F2)/dt] is it e
Thursday, May 13, 2010 at 1:50am by eng
calculus
A= 1/2 bh dA/dt= 1/2 hdh/dt + 1/2 bdb/dt compute, you have h, dh/dt, b, db/dt
Thursday, October 14, 2010 at 7:40pm by bobpursley
calculus
let the width be x let the length be y let the height be h V= xyh dV/dt = xy dh/dt + xh dy/dt + yh dx/dt given x=20, y=12, h = 8 dx/dt = 5 dy/dt = -4 dh/dt = 0 Plug in those values into dV/dt
Wednesday, January 5, 2011 at 9:05pm by Reiny
CALCULUS
Pretty similar to the truck and the police car: Area = A = pi r^2 dA/dt = 2 pi r dr/dt (which by the way is the circumference times the outward speed logically enough.) part 2 is rate of volume change Vol = V = pi r^2 h where h is thickness dV/dt = pi r^2 (dh/dt) + h (2 pi r ...
Thursday, April 8, 2010 at 2:20am by Damon
Calculus
If x = t^2 + 1 and y = t^3, then d^2y/dx^2 = I know I can solve for t in terms of x and substitute that into y = t^3 and find the double derivative. I also know that I can take the derivative of x and y then divide dy/dt by dx/dt. Then take the derivative to get the answer. ...
Thursday, May 15, 2008 at 5:02pm by Anonymous
calc
Draw your little triangle. cos a = x/s where s is the string length (the hypotenuse) and x is the horizontal distance from the flyer. x = s*cos a dx/dt = ds/dt cos a - s*sin a da/dt At our moment, s=100, so 8 = ds/dt cos a - 100 * sin a da/dt Still not home free. What are ds/...
Friday, December 16, 2011 at 4:41pm by Steve
Calculus
let the base be x let the height be y then A = xy dA/dt = x dy/dt + y dx/dt but dA/dt = 0 x dy/dt = -y dx/dt given: dx/dt = 3, find : dy/dt when x = y x dy/xt = -x(3) dy/dt = -3 So at the moment when it turns into a square, the height is decreasing at 3 inches/second
Thursday, March 21, 2013 at 10:12pm by Reiny
Calculus
1)Suppose Q = x^3 y^2 . If [dQ/dt] = −1 and [dx/dt] = 2, find [dy/dt] when x = 4 and y = 5 . [dy/dt] =______ 2)Let A be the area of a circle with radius r. If [ dr / dt ] = 2, find [ dA / dt ] when r = 3
Tuesday, November 3, 2009 at 9:43pm by Mulan
Calculus
write the functions. revenue= number books sold * price book dRev/dt=n dp/dt + p dn/dt you are given n, p and dp/dt, and dn/dt calculate. For the second part, set dRev/dt to 5000 find dn/dt given n, p, dp/dt I will be happy to critique your work.
Sunday, November 25, 2007 at 5:26pm by bobpursley
math
given: dx/dt = 5 , dy/dt = -6 when x=3 and y = 4 , hypotenuse = 5 , (the infamous 3-4-5 right-angled triangle) H^2 = x^2 + y^2 2H dH/dt = 2x dx/dt + 2y dy/dt dH/dt = (x dx/dt + y dy/dt)/H = (3(5) + 4(-6))/5 = -9/5 at that moment of time, the hypotenuse is decreasing at a rate ...
Monday, November 26, 2012 at 4:46pm by Reiny
science
Which of the following equations correctly describes the relationship between the rate at which NO2 and Cl2 are consumed in the following reaction? 2 NO2(g) + Cl2(g) → 2 NO2Cl(g) A. -d(NO2)/dt = 1/2 [d(Cl2)/dt] B. -d(NO2)/dt = 2 [d(Cl2)/dt] C. -d(NO2)/dt = 2 [-d(Cl2...
Monday, May 16, 2011 at 8:19pm by dude
chemistry
Which of the following equations correctly describes the relationship between the rate at which NO2 and Cl2 are consumed in the following reaction? 2 NO2(g) + Cl2(g) → 2 NO2Cl(g) A. -d(NO2)/dt = 1/2 [d(Cl2)/dt] B. -d(NO2)/dt = 2 [d(Cl2)/dt] C. -d(NO2)/dt = 2 [-d(Cl2...
Monday, May 16, 2011 at 8:19pm by dude
calculus
p^2 + 2 q^2 = 1100 2 p dp/dt + 4 q dq/dt = 0 dp/dt = -(q/p) dq/dt R = p q price times quantity dR/dt = p dq/dt + q dp/dt = A dp/dt so A is just q when q = 20 p^2 + 2(400) = 1100 p^2 = 300 p = 10 sqrt 3 dR/dt = q dp/dt = 20*4 = 80
Saturday, October 27, 2012 at 11:31pm by Damon
Math(Please help. Thank you)
Is number 3 considered a related rates problem? I suppose so. I should have been more careful about chain rule to show you what I did. 6p + x + xp =94. 6 dp/dx + dx/dx + x dp/dx + p dx/dx = 0 times dx/dt 6 dp/dx*dx/dt + dx/dx*dx/dt + x dp/dx*dx/dt + p dx/dx*dx/dt = 0 6 dp/dt +...
Sunday, May 1, 2011 at 9:41am by Damon
calculus
first find dr/dt. The diameter changes twice as fast as the radius. v = (4/3) pi r^3 dv/dt = 4 pi r^2 dr/dt so 1 = 4 pi (r^2) dr/dt but r^3 = (3/4)(36)/pi so r = 2.05 ft so 1 = 4 pi (4.2) dr/dt so dr/dt = .019 ft/min D = 2 r dD/dt = 2 dr/dt = .038 ft/min another way rate of ...
Wednesday, October 6, 2010 at 5:09pm by Damon
calculus
the rate of ordinate change is dy/dt. x^2 + y^2 = 100 2x dx/dt + 2y dy/dt = 0 when x=8, y=6, so 2(8)(72) + 2(6) dy/dt = 0 12 dy/dt = -1152 dy/dt = -96 in/s
Wednesday, November 7, 2012 at 4:16pm by Steve
diffirential calculus
did you make a diagram? let her distance from the lightpole be x ft let the length of her shadow be y ft by similar triangles ... 6/y = 10/(x+y) 6x + 6y = 10y 6x = 4y 6 dx/dt = 4 dy/dt we are given: dx/dt + dy/dt = 2 ft/sec dx/dt = 2 - dy/dt so 6(2 - dy/dt) = 4 dy/dt 12 - 6dy/...
Sunday, September 25, 2011 at 12:13am by Reiny
calculus (related rates)
distance=sqrt(y^2 + x^2) ddistance/dt= 1/2distance *( 2ydy/dt+2xdx/dt) now examine y dy/dt= x ln(x) (ln(x)+1) dx/dt ddistance/dt=rateyou want=1/2distance*(2xlnx+1)17cm/sec + x dx/dt) check that, I typed it in a hurry.
Tuesday, October 27, 2009 at 9:05pm by bobpursley
Math Calculus
Reini - How did you ended up getting x dx/dt + y dy/dt=0? my professor said something with a^2 + b^2 = c^2 then differentiate it so 2a(da/dt) + 2b(db/dt) = 2c(dc/dt) so a^2+b^2=c^2 a^2 + 6^2 = 30^2 so a=sqrt(864) then I differentiate let da/dt = 1 b = 6 c=30 2a(da/dt)+2b(db/dt...
Friday, July 8, 2011 at 10:06am by Meg
Math Calculus
Reini - How did you ended up getting x dx/dt + y dy/dt=0? my professor said something with a^2 + b^2 = c^2 then differentiate it so 2a(da/dt) + 2b(db/dt) = 2c(dc/dt) so a^2+b^2=c^2 a^2 + 6^2 = 30^2 so a=sqrt(864) then I differentiate let da/dt = 1 b = 6 c=30 2a(da/dt)+2b(db/dt...
Friday, July 8, 2011 at 10:06am by Meg
calculus
No. You are given db/dt Using the pyth theorm c^2= b^2 + h^2 dc/dt=0= 2b db/dt + 2h dh/dt solve for dh/dt in terms of b,h, db/dt this is what related rates means.
Monday, November 5, 2007 at 8:58pm by bobpursley
calculus
multipy both sides by (x-y) x+y=x^3 -yx^2-xy^2-y^3 check that. dx/dt+dy/dt= 3x^2 dx/dt-2yx dx/dt-x^2dy/dt-y^2dx/dt-3y^2 dy/dt gather terms.... dx/dt(1-3x^2+2yx+3y^2)=dy/dt (-1-x^2-3y^2) check that carefully, it is easy to make an error in sign. solve for dy/dt
Sunday, July 4, 2010 at 6:14pm by bobpursley
calculus
a particle moves along the curve xy=10. if x=2 and dy/dt=3, what is the value of dx/dt. i'm guessing this is something to do with parametric equations. if x is 2, then y=5. but how do i get dx/dt. you have to differentiate the equation with respect to t so xy=10 x(dy/dt...
Saturday, April 21, 2007 at 3:11pm by Anonymous
Calculus
look at the triangle. c^2=b^2+h^2 b= base, h=height take derivitave d c^2/dt=0=2bdb/dt + 2h dh/dt b=4, db/dt=3ft/sec h=sqrt(18^2-4^2) find dh/dt
Sunday, October 30, 2011 at 7:29pm by bobpursley
calculus
v = u^5 v = 7sqrt(w) - wz dv/dt = 5u^4 du/dt = 7/(2sqrt(w)) dw/dt - (w dz/dt + z dw/dt)
Tuesday, October 11, 2011 at 12:31pm by Steve
Calculus
Let the distance of the bottom of the ladder from the wall be x, and let the distance of the top of the ladder from the floor be y. x^2 + y^2 = 256 You want to know dy/dt when dx/dt = 3 and x = 2. At that time, y^2 = 252 and y = 15.87 2x *dx/dt + 2y*dy/dt = 0 dy/dt = -(x/y)*dx...
Saturday, March 12, 2011 at 12:20am by drwls
related rates problem-calculus
The balloon is spherical, so V = (4/3)(pi)r^3 SA = 4(pi)r^2 Differentiate both with respect to time. dV/dt = 4(pi)r^2(dr/dt) dSA/dt = 8(pi)r(dr/dt) We're given the rate of change in SA and need to find the rate of change in volume. Let's write an equation for it. (dV/...
Thursday, December 30, 2010 at 3:25pm by Marth
chemistry
If aA + bB ==> cC + dD, rate of rxn = -(1/a)(dA/dt) = -1/b(dB/dt) etc. So wouldn't rate of reaction equal -(1)(dCl2/dt) = -(1/3)(dF2/dt) = (1/2)(dClF3/dt) Check me out.
Friday, May 29, 2009 at 7:33am by DrBob222
Math
xy = 5 , use the product rule and differentiate with respect to t x(dy/dt) + y(dx/dt) = 0 when x= 1 ---> (1)y = 5, so y=5 now sub in all that stuff in x(dy/dt) + y(dx/dt) = 0 (1)(dy/dt) + 5(3) = 0 dy/dt = -15
Sunday, March 15, 2009 at 10:00pm by Reiny
Maths
y= 4sqrt(4x+1) dy/dt= 4*1/2*1/sqrt(4x+1)*4dx/dt you are given dx/dt, solve for dy/dt now, since r=sqrt(x^2+y^2) dr/dt= 1/2 *1/sqrt(x^2+y^2)* (2xdx/dt+2ydy/dt) solve for dr/dt
Tuesday, November 29, 2011 at 7:07pm by bobpursley
Calc 3
Try a circle with parameter t=θ x=cos(t) y=sin(t) dx/dt=-sin(t) dy/dt=cos(t) at t=0, (dx/dt,dy/dt)=(0,1) at t=π/4, (dx/dt,dy/dt)=(-√2/2,√2/2) ...etc Here: x= e^t y=te^t z=te^(t^2) (1,0,0) Solve for t at the point (1,0,0) gives t=0 (the only...
Wednesday, November 10, 2010 at 11:24pm by MathMate
calculus
Differentiate both sides with respect to t: dy/dt = d(sqrt(1+x^3))/dx * dx/dt =(3x²/(2sqrt(1+x³)))*dx/dt So given x=2,y=3 and dy/dt=3 cm/s substitute in formula above to solve for dx/dt. I get dx/dt=2.
Monday, February 21, 2011 at 12:58pm by MathMate
MATH
So we have 1/x + 1/y = 1/5 differentiate with respect to t (-1/x^2)dx/dt + (-1/y^2)dy/dt = 0 (-1/x2)dx/dt = (1/y^2)dy/dt dx/dt = (-x^2/y^2)(dy/dt) given: when y = 9 1/x + 1/9 = 1/5 1/x = 4/45 x = 45/4 and dy/dt = ???? , not clear what you mean by 16 CM^(-1) what ever it is, ...
Sunday, May 5, 2013 at 8:42am by Reiny
calculus 1
if the angle is θ, and the string length is s, and the horizontal distance the kite has flown is x, sinθ = 100/s cosθ dθ/dt = -100/s^2 ds/dt x^2 + 100^2 = s^2 2x dx/dt = 2s ds/dt, so ds/dt = x/s dx/dt = cosθ dx/dt so, dθ/dt...
Tuesday, February 26, 2013 at 6:18pm by Steve
Calc
1. Determine an expression for dy/dt if x^2+2y^2=8 and dx/dt=3. 2. A point is moving along the right branch of a hyperbola defined by 4x^2-y^2=64. What is dy/dt when the point is at (5, -6) and dx/dt=3? I will start you on the first, using implicit differention. x^2+2y^2=8 2x ...
Tuesday, May 8, 2007 at 9:39pm by Icy
Calculus
Let the independent variable be s = length of one side of the cube. As you mentioned, V(s) = s³ S(s) = 6s² dV/dt = dV/ds*ds/dt = 3s² ds/dt = 24 ... (1) dS/ds = dS/ds*ds/dt = 12s ds/dt = 12 ...(2) Solve for s and ds/dt by substitution or dividing (1) ...
Tuesday, December 7, 2010 at 8:40pm by MathMate
Calc
V = Pi(r^2)(h) dV/dt = pi(r^2)dh/dt + pi(h)(2r)dr/dt sub in the known values -3 = pi(300^2)(-.0003) + pi(.004)(600)dr/dt solve for dr/dt now in A = pi(r^2) dA/dt = 2pi(r)dr/dt = 2pi(300)(above value for dr/dt) = ....
Monday, February 25, 2008 at 9:06pm by Reiny
Physics
F = m a = m w^2 r where w = 2 pi f let u = tangential velocity let v = radial velocity = w r dv/dt = w dr/dt at = du/dt = d/dt(wr) = w dr/dt ar = d^2r/dt^2 = dv/dt= (w^2)r so w dr/dt = w^2 r dr/dt = w r or dr/r = w dt ln r = w dt + c' r = e^(wt + e^c') = C e^wt that is...
Thursday, February 10, 2011 at 4:48pm by Damon
Calculus I
dR/dt = .3 ohms/s I = 18V/R d/dt(I) = d/dt(18V/R) dI/dt(I) = dR/dt(18V/R) dI/dt = dR/dt*(-18/R**2) dI/dt = .3*(-18/4**2) dI/dt = -.3375amp/s Hope you understand my work! Cheerz
Monday, March 1, 2010 at 9:48pm by Zen
Calculus-edited
Let angle of elevation=θ height of plane = H horizontal distance from observer = x tan(θ)=x/H Use implicit differentiation d(tan(θ))/dt = d(x/H)/dt sec²(θ)dθ/dt = (dx/dt)/H dθ/dt=(1/(Hsec²(&theta...
Sunday, November 1, 2009 at 5:20pm by MathMate
Math(Please help. Thank you)
3) Suppose that the price p (in dollars) and the demand in x(thousands) of a commodity satisfy the demand equation 6p + x + xp =94. How fast is the demand changing at times when x= 4 and p=9 and the price is rising at the rate of $2 per week. Would I take the derivative and ...
Sunday, May 1, 2011 at 9:41am by Damon
Calc
dV/dt= 4/3 PI 3 r^2 dr/dt solve for dr/dt given dv/dt Then dS/dt=4PI 2r dr/dt, knowing dr/dt solve for dS/dt and it is done.
Sunday, March 15, 2009 at 10:03pm by bobpursley
calculus
For question a, y = 3x^2, so dy/dt = 6x dx/dt dy/dt = 6(2) * 3 dy/dt = 36 For question b, as t approacing infinity, x is also approaching infinity (the object is moving along the track of the function, remember(, then dy/dt is also approaching infinity in vertical sense... For...
Sunday, October 18, 2009 at 6:16pm by Andre
Thermodynamics
a) Since it is a constant pressure heating, dQ = M Cp dT = [K*M*R/((K-1)]*dT Use that to determine the temperature changle dT, and add that to 80 F. You need to specify the units of R. They should be Btu/lbm*degF b) dU = M Cv dT = [M/(K-1)]dT c) dH = Cp*dT = dQ d) dS = ...
Saturday, March 6, 2010 at 11:53am by drwls
calculus
dV/dt = kA. V = (4/3) π r^3 and A = 4 π r^2 dV/dt = d/dt((4/3) π r^3) = (4/3) π 3 r^2 (dr/dt) Now let's plug that into the first equation: (4/3) π 3 r^2 (dr/dt) = k A = k(4 π r^2) = 4 π k r^2 So when we ...
Tuesday, October 18, 2011 at 3:01pm by Steve
AP calculus AB
dV/dt = 9 = surface area * dh/dt 9 = (pi r^2)(dh/dt) but h = 3 r so dh/dt = 3 dr/dt so 9 = (pi r^2)(2 dr/dt) but r = 3 so 9 = 9 pi (2 dr/dt dr/dt = 1/2pi
Wednesday, December 29, 2010 at 4:47am by Damon
Calculus
V=1/2 PI r^2 h dv/dt= 1/3 PI (r^2 dh/dt + 2hr dr/dt) now relate dr/dt to dh/dt (proportion) then solve for dv/dt given dh/dt
Saturday, September 24, 2011 at 2:52pm by bobpursley
calculus
bobpursely is right, the area of 18 in^2 has nothing to do with it. Here is how I did it D^2 = 2s^2 D = √2 s dD/dt = √2 ds/dt 3 = √2 ds/dt ------> ds/dt = 3/√2 P = 4s dP/dt = 4ds/dt=4(3/√2) = 12/√2 in/min which...
Thursday, October 18, 2007 at 9:18pm by Reiny
calculus
y = x^2 + 8 dy/dx = 2 x dy/dt = dy/dx * dx/dt dy/dt = 2x * 8 = 16 x s = distance from origin s^2 = x^2+y^2 2 s ds/dt = 2 x dx/dt +2 y dy/dt so s ds/dt = x dx/dt + y dy/dt so s ds/dt = [8 x + (x^2+8)(16 x)] ds/dt = [8 x + (x^2+8)(16 x)]/[x^2 +(x^2+8)^2]^.5 = [16 x^3 + 136 x...
Wednesday, October 6, 2010 at 3:42pm by Damon
calulus
distance to origin=sqrt(x+ x^2) d distance/dt= 1/(2sqrt(x+x^2)*(dx/dt+ 2xdx/dt) you have x, dx/dt solve for ddistance/dt
Thursday, November 19, 2009 at 7:35pm by bobpursley
calc
I will assume you meant to type y = 2x^2 + 1 dy/dt = 4x dx/dt given dy/dt = -2 when x = 3/2 -2 = 4(3/2) dx/dt -2 = 6 dx/dt dx/dt = -2/6 = -1/3
Tuesday, December 27, 2011 at 10:38pm by Reiny
Calculus
The vloume increase rate is dV/dt = 500 V = (4/3) pi R^3 dV/dt = (12/3)pi R^2 dR/dt = 4 pi R^2 dR/dt You can use that equation to compute the dR/dt expansion rate for any value of R. Note that that dV/dt equals the instantaneous surface area times dR/dt.
Sunday, November 1, 2009 at 8:39am by drwls
calculus
Well I assume that z is the diagonal. x^2+y^2 = z^2 2 x dx/dt + 2 y dy/dt =2 z dz/dt 4 dz/dt + 3 k dz/dt = dz/dt 4 + 3 k = 1 k = -1
Wednesday, April 27, 2011 at 2:14am by Damon
Calculus
V = s^3 dV/dt = 3v^2 ds/dt when s = 5, dV/dt = 2 2 = 3(25) ds/dt ds/dt = 2/75 A = 6s^2 dA/dt = 12s ds/st = 12(5) (2/75) = 8/5 inches^2 / min
Wednesday, January 30, 2013 at 4:37pm by Reiny
Engineering Kinematic
When t = 1, dx/dt = 5t = 5 m/s From v = dx/dt = 5t, and the starting conditions, you can conclude that x = (5/2)t^2. x = 5/2 = 2.5 when t = 1 y = 0.5*(2.5)^2 = 3.125 when t = 1 The distance from the origin in sqrt[x^2 + y^2]. At t=1, this is D = sqrt[2.5^2 + 3.125^2]= 4.002 ...
Saturday, October 16, 2010 at 4:49am by drwls
Calculus
height y = 12 - 16t^2 shadow at x, similar triangles, so x/12 = (x-4)/y or, xy = 12x - 48 y dx/dt + x dy/dt = 12 dx/dt y=8 when t=1/2 x=6 when y=8 (12 - 16t^2) dx/dt + x (-32t) = 12 dx/dt at t=1/2, 8 dx/dt - 96 = 12 dx/dt dx/dt = 96/-4 = -24 ft/s
Tuesday, April 24, 2012 at 12:05am by Steve
calculus
V=PI*r^2 h dv/dt=0=PIr^2 dh/dt + 2PI r h dr/dt solve for dr/dt, you are given dh/dt.
Saturday, March 16, 2013 at 10:57pm by bobpursley
Calculus
You mean 18 / 6 = (x + y) / y we know dx/dt, we need dy/dt then the tip moves at dx/dt + dy/dt 18 y = 6x + 6 y 12 y = 6 x 12 dy/dt = 6 dx/dt dy/dt = .5 dx/dt so dy/dy = 3/2 = 1.5 and the sum 3+1.5 = 4.5 ft/sec
Sunday, February 6, 2011 at 6:12pm by Damon
Math
y = 3x^2 - 5x = 3(g(t)^2 - 5g(t) dy/dt = 6 g(t) d(g(t))/dt - 5 d(g(t))/dt = 6(g(14)) d(g(14))/dt - 5 d(g(14))/dt = 6(-4)(2) - 5(2) = -58
Wednesday, March 23, 2011 at 10:19pm by Reiny
Calculus
I will do one, and be happy to check your thinking. q=x^3 y^2 dq/dt= 2x^2 y dy/dt+ 3y^2x^2 dx/dt put in dq/dt, dx/dt, and find dy/dt ..
Tuesday, November 3, 2009 at 9:43pm by bobpursley
Calculus
There is 1 error in the above answer. 11dy/dt = 6 dx/dt is true dx/dt = 6 is also true but dy/dt is not 6/11 ft/sec the 6 must be multiplied by the 6 from dx/dt giving dy/dt = 36/11
Thursday, September 24, 2009 at 3:40am by Jarred
math
dV/dt = 3x^2 dx/dt 96 = 3(4^2)dx/dt dx/dt = 96/48 = 2 cm/second A = 6x^2 dA/dt = 12x dx/dt dA/dt = 12(4)(2) = 96 cm^2/sec
Wednesday, August 17, 2011 at 10:28pm by Reiny
Calculus
A line through the origin, rotates around the origin in such a way that the angle, ¦È, between the line and the positive x-axis changes at the rate of d¦È/dt for time t¡Ý0. Which expression gives the rate at which the slope of the line ...
Wednesday, December 8, 2010 at 10:39pm by Anna
chemistry
rate of change is dA/dT = (1/4)dB/dT = (1/2)dC/dT = 0.72 Solve for dA/dT, dB/dT, dC/dT
Thursday, February 28, 2013 at 8:05pm by DrBob222
calculus
V = pi r^2 L ln V = ln pi + 2 lnr + lnL d/dt (lnV) = 0 + (2/r) dr/dt + (1/L) dL/dt dL/dt = - (2L/r) dr/dt When r = 1.8, 128 pi = pi*(1.8)^2 L L = 39.51 inch You know dr/dt. Use the dL/dt formula
Tuesday, December 27, 2011 at 10:05pm by drwls
physics
wr = v a = r dw/dt 1.4 = r dw/dt dw/dt = angular acceleration = 1.4/r = 2.8/.57 assume constant angular deacceleration radial acceleration = w^2 r tangential acceleration = r dw/dt (we know dw/dt from above) w r = v = 3 m/s at t = 0 wo = 3/r w = wo - (dw/dt)t that gives you w^...
Friday, November 26, 2010 at 5:02pm by Damon
Calculus
dy/dt = 6x(dx/dt) so at (2,12) dx/dt = 3 then dy/dt = 6(2)(3) = 36 If dx/dt is always 3, then dy/dt = 18x so as x --> + infinity , 18x ---> + inf. and dy/dt --> + inf. for c) I think you meant to say, "then what happens to dx/dt as t --> +...
Sunday, October 18, 2009 at 3:24am by Reiny
calc 3
there are diagonals along each face, but thety probably want the diagonal of the brick: d^2 = l^2 + w^2 + h^2 2d dd/dt = 2l dl/dt + 2w dw/dt + 2h hd/dt when (l,w,h) = (7,5,5) d = sqrt(99) = 3sqrt(11) 3sqrt(11) dd/dt = 2*7*6 + 2*5*6 + 2*5*(-4) 3sqrt(11) dd/dt = 104 dd/dt = 104...
Friday, September 21, 2012 at 4:34pm by Steve
calculas
A = Lw dA/dt = L dw/dt + w dL/dt but dL/dt = -2 and dw/dt = 2 dA/dt = 2L - 2w = 2(L-w) So it depends on the size of the rectangle, If the rectangle is a square (L=w), then area would remain constant, if L > w, the area is increasing, and if L < w ......
Tuesday, December 7, 2010 at 9:39pm by Reiny
Math Calc
x^2 + y^2 = 25 2x dx/dt + 2y dy/dt = 0 2(-4) dx/dt + 2(3)(9) = 0 -8 dx/dt + 54 = 0 dx/dt = 54/8 = 27/4 = 6.75 makes sense; the particle is moving up to the right.
Sunday, November 25, 2012 at 10:07pm by Steve
math
x^2 + y^2 = 100 , where x is the base, y the height 2x dx/dt + 2y dy/dt = 0 given: dx/dt = 2 , and x = 6 then 36+y^2 = 100 y^2 = 64 y = 8 in 2x dx/dt + 2y dy/dt = 0 2(6)(2) + 2(8)dy/dt = 0 dy/dt = -24/16 = -3/2 it is sliding down at 3/2 m/sec
Friday, May 3, 2013 at 8:35am by Reiny
calculus
make a sketch At a time of t hrs, let the distance the police car is from the intersection be x miles let the distance the speeding car is from the intersection be y miles let the distance between them be d miles d^2 = x^2 + y^2 2d dd/dt = 2x dx/dt + 2y dy/dt d dd/dt = x dx/dt...
Tuesday, January 17, 2012 at 11:53am by Reiny
calculus
take the derivative with respect to t 2x dx/dt+2ydy/dt=0 dx/dt= -y/x dy/dt so when y=8, find x, or x=+-sqrt(100-64) x=+-6 dx/dt=put the values in and compute. Yes, you have two solutions, the x^2+y^2 is not a function, it does not obey simple rules. Think about it. Your ...
Thursday, November 1, 2012 at 8:17pm by bobpursley
calculus
make a diagram showing a right angled triangle with hypotenuse of 8 let the base be x and the height be y given : dx/dt = 1 find: dy/dt when x=5 a) when x=5 , 2+ y^2 = 64 y = √39 x^2 + y^2 = 64 2x dx/dt + 2y dy/dt = 0 dy/dt = -x dx/dt/y = -5(1)/√39 = - .8 ...
Wednesday, October 6, 2010 at 9:49pm by Reiny
calculus
from xy = x + 4 x dy/dt + y dx/dt = dx/dt + 0 when x = 4 , in original 4y = 4+4 y = 2 so when x=4, y=2 and dx/dt = -5 4dy/dt + 2(-5) = -5 + 0 4dy/dt = 5 dy/dt = 5/4 which is c)
Thursday, September 22, 2011 at 10:56am by Reiny
Calculus
draw the triangle (lets W, S) label the West leg W km, South leg Skm Distance between ship x. x= sqrt (W^2+S^2) dx/dt= 1/2 *1/sqrt( ) * (2w *dw/dt + 2S ds/dt) find dx/dt Caculate S, W from 1/2 hr at given speeds. you know dw/dt, ds/dt
Sunday, November 6, 2011 at 5:58pm by bobpursley
Chemistry
I can't write delta on my keyboard; therefore, d = delta, t = time rate = -1/2(d[C4H10]/dt) = -1/13(d[O2]/dt) = 1/8(d[CO2]/dt) = 1/10(d[H2O]/dt)
Sunday, November 27, 2011 at 11:04am by DrBob222
Calculus
If V = IR, then dV/dt = IdR/dt + RdI/dt plug in the given values, and solve for dV/dt (You will have to find R from the first equation)
Monday, December 14, 2009 at 4:11am by Reiny
calculus
PV^k=C take the derivative kPv^(k-1) dV/dt+V^k dP/dt=0 solve for dV/dt dV/dt= -V/Pk * dP/dt check that.
Thursday, April 1, 2010 at 4:22am by bobpursley
chemistry
a. I can't write a delta symbol. delta T will be dT. rate = d[N2]/2*dT = d[CO2]/dT b and c are done the same way except the disappearance is shown with a - sign. rate = d[CO2]/dT = -d[NO]4*dT
Monday, October 15, 2012 at 6:56pm by DrBob222
calc
Volume= 4/3 PI r^3 dV/dt=4PI r^2 dR/dt you are given dV/dt as 14ft^2/hr you are looking for dr/dt so what is the radius at t=3? 210-14*3=4/3 PI r^3, solve for r. put that r into the dV/dt equation, and solve for dR/dt
Monday, February 14, 2011 at 9:07pm by bobpursley
Calculus
Let the independent variable be s = length of one side of the cube. As you mentioned, V(s) = s³ S(s) = 6s² dV/dt = dV/ds*ds/dt = 3s² ds/dt = 24 ... (1) dS/ds = dS/ds*ds/dt = 12s ds/dt = 12 ...(2) Solve for s and ds/dt by substitution or dividing (1) ...
Tuesday, December 7, 2010 at 8:40pm by MathMate
Calculus
a = lw da/dt = w dl/dt + l dw/dt da/dt = 10*8 + 20*3 = 140 cm^2/s
Thursday, October 11, 2012 at 4:28pm by Steve
Calculus
A = lw dA/dt = l dw/dt + w dl/dt for the given case dA/dt = 15(9) + 10(7) = ...
Tuesday, November 9, 2010 at 9:07pm by Reiny
calculus
since you have a calculus class, you probably ought to do it Reiny's way, but sometimes a little simplification can save you some work: If the man is x away from pole, ad his shadow length is s, then using similar triangles, s/2 = (x+s)/6 s = 1/2 x so, ds/dt = 1/2 dx/dt ...
Tuesday, October 16, 2012 at 2:53am by Steve
calculus
Area of sphere = 4 pi r^2 (here r = 10 cm) d area/dr = 8 pi r d area/dt = d area /dr * dr/dt (chain rule) NOW dVolume/dt = area * dr/dt we are given d Volume/dt = 8 mL/min which is 8 cm^3/min from that and area = 4 pi r^2 get dr/dt then use that dr/dt up above to get d area/dt
Saturday, January 3, 2009 at 5:09pm by Damon
calculus
start by drawing a diagram. you should notice that you have a triangle with the ladder as the hypoteneuse. you are given that the lower end is moving away from the wall at 6m/sec, so your dx/dt =6. To find y when x=7: x^2 +y^2 = 25^2 7^2 +y^2 = 625 49 + y^2 = 625 y^2 = 576 y...
Saturday, December 15, 2012 at 11:12am by Elsi
Calculus
from V = x^3 dV/dt = 3x^2 dx/dt dx/dt = 24/(3x^2) = 8/x^2 from A = 6x^2 dA/dt = 12x dx/dt dx/dt = 12/(12x) = 1/x then 8/x^2 = 1/x x^2 = 8x x = 8
Tuesday, December 7, 2010 at 8:40pm by Reiny
Calculus
This is the classic question used by most textbooks to introduce rate of change. using your definitions x^2 + y^2 = 15^2 2x dx/dt = 2y dy/dt = 0 x dx/dt + y dy/dt = 0 a) when x = 9 81+y^2 = 225 y =√144 = 12 also given: dx/dt = 1/2 a) 9(1/2) + 12dy/dt = 0 dy/dt = -4.5...
Sunday, February 5, 2012 at 4:20pm by Reiny
calc
dV/dt = d/dt[(pi/3)*R^2*H] = 30 ft^3/min = (pi/3)(1/4)*d/dt[H^3] since H= 2R dV/dt = 30 = (pi/4)*3H^2*dH/dt Solve for dH/dt when H = 18
Saturday, November 26, 2011 at 4:01am by drwls
Maths - Calculus
f'=d3/dt-d/dt (t^4=0-4t^3 g'=d/dt (sin(4t))= cos4t * d4t/dt=4cos4t ARRRRGGG. Quotent rule in ASCII That is too much algebra for me to do now, maybe later.
Sunday, February 13, 2011 at 8:14am by bobpursley
calculus
Rate at which area is changing, dA/dt where A= 1/2 b*height dA/dt= 1/2 b dh/dt + 1/2 h db/dt
Monday, November 5, 2007 at 8:58pm by bobpursley
Calculus
let the truck' distance from the intersection be x miles make a diagram and you should have a right-angles triangle with sides x,1, and let the hypotenuse be y given dx/dt = 60 mph find dy/dt when x = 3 y^2 = x^2 + 1 2y dy/dt = 2x dx/dt dy/dt = (x dx/dt)/y when x = 3, y...
Monday, October 25, 2010 at 11:21am by Reiny
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