Saturday

May 30, 2015

May 30, 2015

Total # Posts: 21,076

**calculus**

at 1, y = 2 at 3, y = 0 dy/dx = -2x + 3 = 0 if x = 3/2 at x = 3/2, y = 2.25 so max at x = 3/2 and min at x = 3
*October 31, 2014*

**calculus**

df(x)/dx = 3 x^2 that is the slope at x = 3 slope = 3*9 = 27 so y = 27 x + b put in point at x = 3 to find b 27 =27 * 3 + b so -54 = b so y = 27 x - 54 at x = 2.7 y = 27 * 2.7 -54 = 18.9 the real answer would be y = 19.7
*October 31, 2014*

**statistics**

http://davidmlane.com/hyperstat/z_table.html
*October 30, 2014*

**Geometry**

yes correct m' = -1/m
*October 30, 2014*

**Social Studies**

Do you really think the former colonists would have won the war if they were a minority in the 13 colonies?
*October 30, 2014*

**Social Studies**

No, it is not a.
*October 30, 2014*

**Social Studies**

I thought I answered :) Looking at the link that Ms. Sue gave you, I think I answered correctly.
*October 30, 2014*

**Social Studies**

Oh, your answer to the Saratoga question is correct for sure.
*October 30, 2014*

**Social Studies**

I think c was true. I do not think more than half the colonists were Loyalists.
*October 30, 2014*

**math**

7 have black or brown total = 4+3+1+2 = 10 7/10 You can multiply top and bottom by 6 if you want, but no different :)
*October 30, 2014*

**Calculus**

3 * (x^10 - 1)^2 * 10 x^9 or 30 x^9 (x*10 - 1)^2
*October 30, 2014*

**Algebra 2**

20 x - 1 y = -200 25 x - 1 y = 0 D = -20 + 25 = 5 Dx = | -200 -1 | | +000 -1 | / 5 = 200/5 = 40 sign ? Dy = | 20 -200 | | 25 +000 | /5 = 5000/5 = 1000
*October 29, 2014*

**Please help-algebra**

yes
*October 29, 2014*

**Please help-algebra**

Jacqueline, please read the problem again.
*October 29, 2014*

**Please help-algebra**

no .15*number + 10 0.15 x + 10
*October 29, 2014*

**Please help-algebra**

Which do you think? 15 cents times the square feet plus a 10.00 trip fee
*October 29, 2014*

**MATH FOR THE OFFICE**

31 2/8 - 29 3/8 = 30 10/8 - 29 3/8 = 1 7/8
*October 29, 2014*

**Math Help Please! ASAP!**

no y + 5 >7 subtract 5 from both sides y > 2 The second one is right
*October 29, 2014*

**Algebra: Answer Check**

No, I do not think so, suspect typo in numerator. It should be possible to factor.
*October 29, 2014*

**Algebra: Answer Check**

-3*16 -8*5 + 2 +7 -48 -40 + 9 -88 + 9 -79
*October 29, 2014*

**Physics**

momentum east = 20*3 = 60 momentum north = 30 * 2 = 60 momentum east = 50*Ve = 60 momentum north = 50*Vn = 60 Ve = 6/5 Vn = 6/5 angle = 45 speed = (6/5) sqrt 2
*October 29, 2014*

**physics**

see the problem just above this one
*October 29, 2014*

**Physics**

F = m g sin 34 = 120 x x = (1/120)(3)(9.8) sin 34
*October 29, 2014*

**Calculus**

a) 973 + .0685 ( 81000 - 20000) b) T = .9 x c) L = 973 + .0685 (.9 x - 20000) d) 973 + .0685 (.9*90000 - 20000) same as a above
*October 29, 2014*

**Calculus**

tan T = h/60 d tan T /dt = dT/dt sec^2 T = (1/60)dh/dt dT/dt = (1/60) cos^2 T dh/dt tan T = 25/60 T = 22.6 deg so cos^2 T = .852 dT/dt = (1/60)(.852) (8) in radians !
*October 29, 2014*

**Algebra**

I got 1 -3 * 16 = -48 +5* 8 = 40 - -2 = 2 +7 = +1
*October 28, 2014*

**math**

about 3+3 = 6
*October 27, 2014*

**Fluid Mechanics**

You are welcome.
*October 27, 2014*

**Fluid Mechanics**

find the pressure at the bottom p = 1 atm + density * g * h 1 atm = about 10^5 pascals or Newtons/m^2 multiply the pressure by the area F = p A A = pi r^2 b) find the pressure halfway up the tank p = 1 atm + density * g * h/2 multiply that by the total area of the side of the ...
*October 27, 2014*

**Physics need help**

P V = n R T find n in V= 1 meter^3, then we will find molar mass later 1.51*10^5 * 1 = n *8.31 (273+0) n = 66.6 mols now a mol of CO has mass 12+16 = 28 grams = .028 Kg so we have .028 * 66 = 1.85 kg /m^3
*October 27, 2014*

**Math Homework**

x^2 + 2 x + 3 > 0 upward opening parabola (holds water) where is the vertex? complete square x^2 + 2 x = y - 3 x^2 + 2 x + 1 = y - 2 (x+1)^2 = y - 2 vertex at (-1 , 2) so y is never below y = 2 x^2 + 2 x + 3 > 2
*October 27, 2014*

**Calculus: need clarification to where the #'s go**

what is an mbox? V = (4/3) pi r^3 S = dV/dr = 4 pi r^2 dS/dr = 8 pi r so dS/dt = 8 pi r dr/dt now find dr/dt if dV/dt = 80 cm^3/s dV = S * dr = 4 pi r^2 dr so dV/dt = 4 pi r^2 dr/dt so dr/dt = ( 1/4 pi r^2 )dV/dt = (20/pi 14^2) so dS/dt = 8 pi 14 (20/14^2 pi) = 80/7 =
*October 27, 2014*

**algebra 2**

c = m d + b 1.7 = 2 m + b 3.7 = 7 m + b =================== -2 = -5 m m = 2/5 so c = (2/5) d + b 1.7 = (2/5)2 + b b = 1.7 - .8 = .9 so c = (2/5) d + 9/10 or 10 c = 4 d + 9
*October 26, 2014*

**Math**

yes yes
*October 26, 2014*

**Algebra**

The function is undefined for x = 1 (x = 1 is not in the domain but otherwise all real x) but the range is from -oo < y < +oo
*October 26, 2014*

**calculus**

f(x) = 5/x f(x+h) = 5/(x+h) [f(x+h) - f(x) ]/h = [5/x+h) -5/x]/h = 5[ x - (x+h) ] /(x^2+xh)h =5 [ -h ] /(x^2+xh)h = -5/(x^2+xh) ======================== if you want use x = 4 right now = -5/(4^2 + 4 h) let h-->0 = -5/16 ======================== I would continue though let h...
*October 26, 2014*

**calculus**

here for example: http://www.sosmath.com/calculus/diff/der00/der00.html
*October 26, 2014*

**typo**

f(x) is a function of x or is it 5/8? the slope for part b is the definition of the derivative in beginning calculus. You are not supposed to know that but google it and the result will show you how to find the limit of: [ f(x+h) - f(x) ] / h as h -->0
*October 26, 2014*

**differential equation**

dA/dt = k(M-A) - cA dA/dt = k M - kA - c A but k - c is a constant call it r dA/dt = kM- rA dA/dt +rA = k M = constant for this case of M
*October 26, 2014*

**math/limits**

(x-3) / [ (x-3)(x+3) = 1/(x+3) so when x is 3 1/6
*October 25, 2014*

**math/limits**

You mean???? [(14+y)^2 - 14^2 ] / y ???? if so [ (14+y-14)(1+y+14)] / y y (y+15)/ y y+15 as y--->0 15
*October 25, 2014*

**College Algebra**

First draw the picture, center at (0,0) and radius = 5 You see that point in Quadrant 3? It makes a triangle with the -y axis hypotenuse 5, bottom 3, 4 down y axis Now draw the tangent to the circle at that point. It will be perpendicular to the radius at that point. Since the...
*October 25, 2014*

**Math**

v^3 = 5.8^3 vsphere = (4/3) pi (5.3/2)^3 subtract
*October 25, 2014*

**physics**

G Me m /r^2
*October 25, 2014*

**csci 120**

f(t) = initial balance ( 1 + r )^t where r = yearly interest percent/100 t is time in integer years after deposit
*October 25, 2014*

**physics**

m g = 690 mg - 1000 kg/m^3 * V g = 36 1000 V g = 690 - 36 = 654 N g = 9.8 so V = 654/(1000 g) rho = m/V = 690/g / .654/g = 1055 kg/m^3 just a little heavier than water (must have expelled all air from her lungs to sink like that)
*October 25, 2014*

**Physics**

friction work done = ke lost = (1/2)m v^2 force = .7 m g = .7 * 66 * 9.8 mass = 66 a = F/m = .7 * 9.8 = 6.86 m/s^2 0 = 4.4 - 6.86 t t = .641 seconds average speed = 2.2 m/s distance = 2.2 * .641 = 1.41 meters
*October 25, 2014*

**Calculus**

and also draw a picture of the circle of radius 2 and center at (0,0) so you get an idea what is going on.
*October 24, 2014*

**physics**

(1/2) m v^2 = m g h so v1 = -sqrt(2 g h) (coming down) h = -2.87 coming down going up same deal but opposite sign for v v2 = + sqrt(2*9.8*1.12) change in momentum = m (v2-v1)
*October 24, 2014*

**Algebra Slope Intercept Form**

slope is -6/2 = -3 look at what Steve did He did it exactly the way I did your last problem!
*October 23, 2014*

**Algebra Slope Intercept Form**

see http://www.jiskha.com/display.cgi?id=1414100500 exactly the same procedure.
*October 23, 2014*

**math**

2 pints then is 4 cups that is 8 half cups
*October 23, 2014*

**Trig/Pre-Calc...**

That is interesting, a little tailwind helps but a lot hurts. also zero has an effect? why? anyway if s = 3 t = .0119 *9 - .308 *3 - .0003 t = +.1071 - .924 - .0003 t = -.8172 seconds (wow, a lot) = -.82 rounded
*October 23, 2014*

**Math**

No if x = 2 y = 20 * 2 + 10 y = 40 + 10 y = 50
*October 23, 2014*

**Math**

to graph it use any two points on the line if x = 0 , y = 10 so (0,10) is one point if x = 532, y = 20*532 + 10 = 10,650 so (532 , 10,650) is a point take ruler and draw line through those points (I would suggest using like x = 5 instead of 532)
*October 23, 2014*

**Algebra Slope Intercept Form**

change in y/change in x = -2/7 = m so y = (-2/7) x + b put in any old point from the table, like (0,-1) -1 = 0 + b so y = (-2/7) x - 1 or 7 y = -2 x - 7
*October 23, 2014*

**Language Arts HELP!**

B is the only sentence in the list that is English.
*October 23, 2014*

**math**

1 gallon = 231 in^3 37 * 10 * 12.5 in^3 (1 gal / 231 in^3) = 20 gallons
*October 23, 2014*

**Finance**

You mean you just deposited once with 27K ? If so amount = 27,000 (1.11)^20 = 27,000 (8.062311536) = 217,682.41 gee, I agree to the penny wonderful stuff that compounding :)
*October 23, 2014*

**Math 12**

The main reason for giving appreciated stock to a charity is to avoid paying any capital gains tax on the stock. but anyway paid 100 * 10 = 1,000 for stock it was worth 100 N when granted got a refund of .6(100 N) = 60 N paid tax = .2(100 N - 1,000) so 60 N - (20 N - 200) = 1...
*October 23, 2014*

**ap calc**

oh, the first one is always v positive v = 2t+2 so when does the second one go - ?
*October 23, 2014*

**ap calc more on d**

they both start out + find out when the first one hits v = 0 then it goes - while the first is + find when the second hits v=0 then they both are - etc
*October 23, 2014*

**ap calc**

b) find the velocity of each when t = 8 v1 = 2(8)+2 = + 18 v2 = -2t +8 = -8 so in opposite directions d ) they start out both moving + when is v1-v2 = 0 ?
*October 23, 2014*

**physics**

vertical problem first Vi = 9.52 sin 24.4 v = Vi - 9.8 t at top v = 0 so 9.8 t = 9.52 sin 24.4 = 3.93 t = .401 seconds to top height h = Vi t - 4.9 t^2 h = 3.93 (.401) - 4.9(.401)^2 h = .789 m now the horizontal problem time = 2 t = .802 seconds because he spends as much time ...
*October 23, 2014*

**Algebra**

slope = -1/5 y = -(1/5)x + b -1 = -3/5 + b b = -2/5 so y = -(1/5)x -2/5 or 5 y = -x -2
*October 22, 2014*

**PHYSICS**

I initial = 4.90 + .565^2 (4.95*2) = 4.90 + .319 (9.9) = 4.90 + 3.16 = 8.06 Ifinal = 4.90 + .2^2(9.9) = 4.90 + .396 = 5.30 oh my, much less angular momentum initial and final = I omega1 = 8.06*2.8 = 22.6 (answer A) = 5.3*omega2 so omega 2 = 22.6/5.3 = 4.26 rad/s Now I think ...
*October 22, 2014*

**physics Damon???**

(i) half (it arrives randomly polarized. The first filter takes out all the x components for example) (ii) None. The x components go out with the first filter. The second filter takes out the y components :) (iii)http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/polcross.html ...
*October 22, 2014*

**Algebra 2**

Assuming you are not allowed to use calculus, complete the square to find the vertex. x^2 + 12 x = y-5 x^2 + 12 x + 6^2 = y - 5 + 6^2 (x+6)^2 = y + 31 vertex at x = -6, y = -31 so never smaller than -31
*October 22, 2014*

**physics**

You are welcome.
*October 22, 2014*

**physics**

it would have to be 8 times as thick 64 cm (pretty thick :)
*October 22, 2014*

**science**

http://curious.astro.cornell.edu/question.php?number=300 Note that if you are in the Northern hemisphere You can see stars that are high in the northern sky all year. It is the ones close to the plane of the earth's orbit that you can only see when you are facing them at ...
*October 22, 2014*

**Sorry**

mistook / for times (bottom*derivative of top - top * derivative of bottom)/bottom^2 (x)/(2+x)= = [(x+2)(1)-x(1) /(x+2)^2 = [ x+2 -x ] /(x+2)2 = 2/(x+2)^2
*October 22, 2014*

**Derivatives**

(2+x) d/dx (x) + x d/dx (2+x) (2 + x) + x(1) 2 + 2 x 2(x+1)
*October 22, 2014*

**physics**

6.3 * sin 34 = 3.52 meters up m g h = 13.2 * 9.81 * 3.52 = 456 so I get -456 J I think you reversed digits
*October 22, 2014*

**physics...damon please help**

delta L/L = k delta T delta L/L = 6.7*10^-6 inches/inch degree F (117 deg F) L = 10 meters =394 inches so delta L = 394 * 6.7 *10^-6 * 117 = .309 inches = .784 cm = .0784 meters
*October 22, 2014*

**COLLEGE PHYSICS**

|v1| = 2|v2| v1^2 = 4 v2^2 so Ke v1 = 4 Ke v2 so 5 Ke2 = 7500 J so Ke2 = 1500 J and Ke1 = 6000 J
*October 22, 2014*

**Trig ?**

I do not understand your symbols, do not have whatever font you are using. I assume this is some kind of a phase shift in the argument of the cotangent.
*October 22, 2014*

**physics**

17 = (1/2) 1.9 t^2 solve for t v = 1.9 t
*October 22, 2014*

**Math**

II. When calculating interest , you need too ______? (1pt) a. Change the percentage to a decimal then multiply the decimal against the amount. --------------------------------- VIII .0450 - .0375 = .0075 .0075 * 1000 = 7.50 or answer c BUT this assumes interest PER MONTH (very...
*October 22, 2014*

**Algebra 1 ?????**

do you mean -2/5x - 9 < 9/10 ??? or (-2/5)(x - 9) < 9/10 or -2/(5x - 9 )< 9/10 or -2/[5(x - 9)] < 9/10 or what ?
*October 22, 2014*

**math**

You mean he checked 25 wheels ????? If so then what times 4 + what times 3 = 25? 1*4 + 21 sure 1*4 + 7*3 2*4 + 17 nope 3*4 + 13 nope 4*4 + 9 sure 4*4 + 3*3 4*5 + 5 nope 4*6 + 1 nope
*October 21, 2014*

**math**

1.65 * 100 = 165
*October 21, 2014*

**Precalculus**

PLEASE PROOF READ - I assume you mean 2.2ft. / HOUR a) A = pi r^2 b) 2.2 t c) 2.2 * 2 2.2 * 2.5 d)A(2) = pi * (4.4)*2 A(2.5) = pi (5.5)^2 e) A(t) = pi (2.2 t)^2 f) A(2) = pi (2.2*2)^2 A(2.5) = pi (2.2*2.5)^2 g) [ A(2.5) -A(2) ]/.5 h) [A(7.)-A(5)]/ 2.5 i) you will see that it ...
*October 21, 2014*

**precalculus**

A = Ai e^kt 2 = e^3k 3 k = ln 2 k = .231 30 = e^(.231 t) ln 30 = .231 t t = 14.7 hours
*October 21, 2014*

**precalculus**

already did this above
*October 21, 2014*

**algebra**

note a may not be 10 or -4 or the problem is undefined (zero denominator)
*October 21, 2014*

**algebra**

(a+10)/(a+4) by dividing top and bottom by (a-10)
*October 21, 2014*

**Physics**

4.63 * 4.10 work "in" in x direction -3.79 * 3.86 work "out" in y direction (braking) 2.16 * -2.45 work "out" in z direction now just add the results (not a vector) 4.63 * 4.10 - 3.79 * 3.86 - 2.16 * 2.45 Joules (scalar but does have sign)
*October 21, 2014*

**math**

Oh, I misunderstood question I think.
*October 21, 2014*

**math**

72 min and 75 min (common multiple?) 72 = 12 * 6 = 3*3 *2*2*2 75 = 5*5*3 so we need 25 * 3 * 8 = 600 minutes = 10 hours
*October 21, 2014*

**Physics**

just did it below kinetic energy at bottom = potential energy at top
*October 21, 2014*

**Physics**

m g h = (1/2) m v^2 v^2 = 2 g h v = sqrt (2 g h) h = 3.27 (1 - cos 35.6) meters g = 9.8 m/s^2
*October 21, 2014*

**Physics**

work done by gravity = change in potential energy in falling from initial height h = L (1-cos theta) h = .8 (1 - cos 40.4) so work=m g h = 2.63*9.8*.8 (1 - cos 40.4)
*October 21, 2014*

**Physics**

2275 = 207.8 t +(1/2)15.6 t^2 solve quadratic for t then v = 207.8 + 15.6 t
*October 21, 2014*

**Physics**

d = Vo t + (1/2) a t^2 219 = 0 + 2.3 t^2 solve for t v = Vo + a t v = 0 + 4.6 t
*October 21, 2014*

**Physics**

here for example Vo = 14.8 a = 11.3 ft/s^2 t = 6.6 sd v = Vo + a t so v = 14.8 + 11.3 * 6.6 = 89.4 feet/second
*October 21, 2014*

**Physics**

http://hyperphysics.phy-astr.gsu.edu/hbase/mot.html You want the box labeled: "Description of motion in one dimension"
*October 21, 2014*

**inequalities**

10x -20 + 11 < 10 -12 + 2x 8 x < 7 x < 7/8
*October 21, 2014*

**Note**

0 = Vo - a t ignore that line, final speed is not zero and is not needed
*October 21, 2014*

**please help! physics**

95 km/hr *1000/3600 = 26.4 m/s in .5 seconds moves 13.2 meters then a = F/m = -2400/1200 = - 2 m/s^2 0 = Vo - a t d = 13.2 + 26.4 t - (1/2) (2) t^2 t = 2 so d = 13.2 + 48.8 = 62 meters d = 13.2 +
*October 21, 2014*