Saturday

August 23, 2014

August 23, 2014

Total # Posts: 17,988

**algebra**

(m-1) or (1-m) 7 - m + 1 = 3 or 7 -1 + m = 3 m = 5 or m = -3 check if m = 5 |m-1| = 4 4 = 4 good if m = -3 |m-1| = 4 good
*May 15, 2014*

**Math - Int Trig**

for every a+bi there is a a-bi solution (x-2i)(x+2i)(x-3i)(x+3i) = 0 (x^2 +4)(x^2+9) = 0 x^4 + 13 x^2 + 36 = 0 ================= (x-i)(x+i)(x+10) = 0 etc
*May 15, 2014*

**Precalculus**

2 x^2 + 4 x = y^2 - 4 y +4 2 x^2 + 4 x = (y-2)^2 x^2 + 2 x - (1/2) (y-2)^2 = 0 x^2 + 2 x + 1 - (1/2) (y-2)^2 = 1 (x+1)^2 - (y-2)^2/(sqrt 2)^2 = 1 Hyperbola, you look up the stuff for it.
*May 15, 2014*

**math**

when x = 0, y = 3 so make a point (0,3) when y = 0, x = -1 so make a point (-1,0) the line goes through those two points and off into the distance left and right
*May 12, 2014*

**Science**

sorry, typo 1.5 * 63 Joules
*May 12, 2014*

**Science**

4.5 * 63 Joules
*May 12, 2014*

**Algebra 1 Answer Evaluation**

Yes, the only solutions to the first problem are the imaginary numbers +/- i sqrt 7 where i is the sqrt of NEGATVE one
*May 12, 2014*

**Algebra 1 Answer Evaluation**

x^2 + 0 x + 7 = 0 x = [ 0 +/- sqrt(-28) ]/2 x = +/- 2 sqrt -7/2 x = +/- sqrt(-7) or +/- i sqrt 7 ================================= x^2 - 0 x -16 = 0 x = [ 0 + /- sqrt (0 +4*16) ]/2 x = +/- 2*4/2 x = +/- 4 what else is new :)
*May 12, 2014*

**math**

position = speed * time + initial position or d = s t + di 90 = s (2) + di 135 = s(3) +di subtract 45 = 3 s - 2 s = s and 135 = 45(3) + di or di = 0 so in the end d = 45 t check that for example does 270 = 45(6) ???
*May 12, 2014*

**math**

-4 = (1/4) (0) + b b = -4 y = (1/4) x -4 or 4 y = x - 16 graph that line
*May 12, 2014*

**math**

(-2 - 2) / (4-6) -4 / -2 2
*May 12, 2014*

**trig**

sin 15 = 135/ hypotenuse tan 15 = 135/d along ground
*May 12, 2014*

**Calculus answer check**

s = .7 t^2 ds/dt = v = 1.4 t 4 = 1.4 t t = 4/1.4 = 2.86 seconds It asked for t given v = 4 m/s
*May 9, 2014*

**maths**

(p-7)(p+6)
*May 6, 2014*

**Pre - Cal**

start at the middle up 4 end up 20 (16 above middle y = kx^2 16 = k(40)^2 16 = k (4)^2(10^2) 1 = 100 k k = .01 so , adding the 4 at the middle y = 4 + .01 x^2 at x = 20 y = 4 + .01 (4)(100) = 8
*May 5, 2014*

**Pre - Cal**

(x+3)^2 = a(y-1) (4+3)^2 = a (-5-1) 49 = -6 a a = -49/6 x^2 + 6 x + 9 = -49/6 (y-1) x^2 + 6 x + 54/6 = - 49 y/6 + 49/6 x^2 + 6 x - 5/6 = -49 y/6 6 x^2 + 36 - 5 = -49 y
*May 5, 2014*

**Pre - Cal**

4y^2+4y-16x=0 y^2 + y = 4 x y^2 + y + 1/4 = 4 (x + 1/16) (y+1/2)^2 = 4 (x+16) vertex at (-16 , -1/2)
*May 5, 2014*

**Calculus**

integral f(t) dt from 5 to 7 sin 7 - sin 5 = .657 - .959 = -.30 if angle is in radians or .121 - .087 = .0347 if angle is in degrees I suspect you left a pi out or something.
*May 5, 2014*

**English**

d cautionary is correct
*May 5, 2014*

**Help math only 1 question easy!**

3 * 2 * 1 = 6
*May 5, 2014*

**physics**

distance = speed * time wavelength = speed * period = speed / frequency = 3 * 10^8 m/s / 76 = 3.95 * 10^6 meters = 3950 km Either you have a typo or you are talking about a super low frequency system that is used to communicate with submarines underwater. It is 360 degrees ...
*May 5, 2014*

**Physics**

7 m/s * 3600 s/hr /1000 m/km = 25.2 km/hr which is about 15 miles/hour 10m/s = 36 km/hr which is about 22 miles/hour If you are really, really fast you might run 100 meters in around 10 seconds :) I am sure you can think of something :)
*May 5, 2014*

**Algebra**

-10 (x^3 - 3 x + 2) /[-5(x-1)] 2 (x^3 - 3 x + 2) / (x-1) 2 (x^2+x-2)(x-1)/(x-1) 2 x^2 + 2 x -4
*May 5, 2014*

**pre calculus**

Vx = 1200 cos 6 Vy = 1200 sin 6 |V| = sqrt (Vx^2 + Vy^2)
*May 5, 2014*

**maths**

18 - 24 j 9 - 8 j
*May 5, 2014*

**maths**

That is not an equation.
*May 5, 2014*

**maths**

[(x+a)(x+b)] / [(x+a)(x+a)] = (x+b)/(x+a)
*May 5, 2014*

**math?**

82 - 5(15) = 82 - 75 = 7
*May 5, 2014*

**AP Physics B**

4.2 * heat of fusion of water 4.2 * 79.5 kcal/kg = 334 kCal
*May 5, 2014*

**maths**

I have no idea. You did not say how much he spent total.
*May 5, 2014*

**physics**

The net horizontal force is 35 -2.9 = 32.1 N
*May 2, 2014*

**Calculus**

if dP/dx = x e^-x^2 then p = -(1/2)e^-x^2 + C 15,000 = -.5 /e + C agree so C = 15,000 + .1839 = 15,000.1839 so p = -(1/2)e^-x^2 + 15,000.18
*May 2, 2014*

**Physics/Calculus**

f = -k x 21714 = k (3) W = (1/2) k x^2 do for x = 1/2 inch then for 1 inch and subtract the half inch result
*May 2, 2014*

**Calculus**

work = integral w dz w = 4.5 (180-z) so work = integral from z = 0 to z = 180 of 4.5 (180-z)dz = 4.5*180 (180) - 4.5 (1/2)(180)^2 = (1/2)(4.5)(180)(180) or half the weight over the whole distance of course :)
*May 2, 2014*

**Physics**

half the weight times the distance
*May 2, 2014*

**Physics**

twice as far (1/2) k x^2 where k = force/distance
*May 2, 2014*

**Math**

2*8 + 2*w = 30
*May 2, 2014*

**Calculus Help and Check**

I gave you my answer which is quite different.
*May 1, 2014*

**calculus help**

delta x = pi/8 x at pi/16 , 3pi/16, 5pi/16, 7pi/16 so 2 cos^3 pi/16 = 1.887 2 cos^3 3 pi/16 = 1.1497 etc add them up and multiply by pi/8
*May 1, 2014*

**calculus help**

Well, I gave you my answer which is quite different.
*May 1, 2014*

**calculus help**

sorry, extra dx in there = f(q) - f(p) f(q) = ln (8+3sin x) f(p) = ln (8+3cos x) f(q)-f(p) = ln [ (8+3sin x)/(8+3cos x) ]
*May 1, 2014*

**calculus help**

the derivative of a definite integral is how much the area changes as you change the limits. d/dx Int from p(x) to q(x) of f(v)dv = [f(q)-f(p)]dx (draw a sketch of that graph)
*May 1, 2014*

**Constituion**

Read the text. I gave a link to it :)
*May 1, 2014*

**Constituion**

http://www.archives.gov/exhibits/charters/constitution_transcript.html
*May 1, 2014*

**Constituion**

Yes, Article 1 is about Congress
*May 1, 2014*

**Math**

domain is where the function is defined. If the denominator is zero, no calculator can produce a big enough answer :)
*May 1, 2014*

**Constituion**

All of it.
*May 1, 2014*

**Chemistry**

.25 (100/65)
*May 1, 2014*

**Calculus Help Please Urgent!!!**

Oh, I take that back, their function includes the proper period and amplitude.
*May 1, 2014*

**Calculus Help Please Urgent!!!**

Hey, I just gave you the method, not the answer You have to put in the given period and amplitude
*May 1, 2014*

**Calculus Help Please Urgent!!!**

dV/dt = f(t) = (3/10) sin (2 pi t/3) V = integral of that dt = -(3/10)(3/2pi) cos (2 pi t/3) = -(9/20pi)cos (2 pi t /3)
*May 1, 2014*

**Chemistry**

I also typed it wrong 4.184 not 4,184
*May 1, 2014*

**Chemistry**

Specific heat water - 4.187 kJ/kgK = 4,187 J/gC
*May 1, 2014*

**Chemistry**

change of water temp = +2 deg C heat energy into water = Cwater*m *2 deg heat energy out of rock = 532.1 J so 531 J = Cwater * m * 2 Cwater is specific heat of water in Joules/(gram deg C)
*May 1, 2014*

**science**

carbon credits? http://en.wikipedia.org/wiki/Carbon_credit
*May 1, 2014*

**Physics**

Now think! Did the mass of the sphere change? Was it a nuclear reaction? What dos the fluid pressure have to do with good old Archimedes? How long would the temperature of the sphere and the fluid stay different? LOL How did the volume inside the sphere change if the glass did...
*May 1, 2014*

**Pysical science**

.05 kg = 50 grams 50 g / 7.9 g/cm^3 = (50/7.9) cm^3
*May 1, 2014*

**Physics quick help please**

Voltage * charge = work done by E field on charge Same thing really Volts = E * d Use METERS volts, Coulombs
*May 1, 2014*

**PHYSICS URGENT**

Volts + charge = work done If + charge moves in direction of E field, potential goes down .02 meters E = V/d
*May 1, 2014*

**algebra**

sure (5) /2 = 2 Remainder 1 which is exactly the same as 2 1/2 That is really what "remainder means" .
*May 1, 2014*

**world history**

That is corrct.
*May 1, 2014*

**Physics**

P V = NRT = constant if n and T constant so P1 V1 = P2 V2 if V2 is half V1 then P2 is TWICE P1 difference in pressure from one side of piston to the other = 1 atm which is about 10^5 Pascals or Newtons.m^2 F = P A = 10^5 newtons.m^2 * pi .23^2 / 4
*May 1, 2014*

**Math**

For example (-1,-3/4) (4,-3/4) (4,3) (-1,3)
*May 1, 2014*

**Physic II**

Nothing happens with 100% efficiency
*April 30, 2014*

**Physics ? geometry**

I do not know V, the initial Volume of gas so can not do the problemP V = n R T P dV + V dP = 0 if n R and T do not change P initial = 10^5 Newtons/m^2 ( or Pacals) dV = (24*10^-4) x V = I have no idea. You left this out. dP = 5*9.81/(24*10^-4)
*April 30, 2014*

**physics**

Ke = (1/2) m v^2 + (1/2) I omega^2 v = omega r so omega = v/r Ke = (1/2) m v^2 + (1/2) I v^2/r^2 = m g (.25) (1/2) m v^2 + (1/2) (2/5) m v^2 = .25 m g (7/10) v^2 = .25 * 9.81
*April 30, 2014*

**geometry**

17 * 17 * 1/6 = 48.167 ft^3 1 yd^3 = 3*3*3 = 27 ft^3 48.167 ft^3/27 ft^3/yd^3 = 1.784 yd^3 1.784 yd^3 * $ 40/ yd^3 = $ 71.36 by the way, concrete people refer to a cubic yard as a "yard". They are not likely to send a truck with 1.784 yards, so you will pay for 2 ...
*April 29, 2014*

**English**

A is wrong. you're means "you are" not "your".
*April 29, 2014*

**Calculus Help and Check**

calculate C' = dC/dx at x = 2000 then dC = C' dx dC = C' (4000-2000) C' = 3 - 20 + 40 = 23 dC = 23 (2000) = 46,000
*April 29, 2014*

**Physics**

.6 seconds is quarter period so period = .6*4 = 2.4 s
*April 29, 2014*

**Physics**

(1/2) m Vmax^2 if x = a sin w t v = a w cos wt so Vmax = a w a is amplitude w is circular frequency = 2 pi f so Ke max = (1/2) m (a^2 w^2) = 2 pi^2 m a^2 f^2
*April 29, 2014*

**Math**

Perhaps they want us to assume it is possible. 4 out of the 15 sides are less than 5 so about 4/15 in each roll so in each roll the probability of NOT getting less than 5 is 11/15 so the probability of NEVER getting less than 5 is (11/15)^45 so our answer is 1 - (11/15)^45 ...
*April 29, 2014*

**Math**

The concept of a 15 sided cube startles me. Did you make this question up yourself?
*April 29, 2014*

**social studies 9**

What country?
*April 29, 2014*

**Math**

Hector cash = 450 + 20 t Tim cash = 1200 - 30 t Are you interested in how many weeks until they are equal? If so 1200 - 30 t = 450 + 20 t 50 t = 1200-450 t = 15 weeks
*April 29, 2014*

**Physics**

(1/2) m v^2 = potential energy potential energy is mgh for low altitude but that will not work for high altitude where g is less than 9.81 m/s^2 increase in potential = G M m (1/Re - 1/(Re+h) call z = Re +h (1/2) v^2 = G M (1/Re - 1/z) solve for z then h = z - Re
*April 29, 2014*

**Physics**

v^2/r = 8.26 F/m = local g = G M/r^2 = 8.26 6.67*10^-11 * Mass earth/r^2 = 8.26 solve that for r then v^2 = 8.26 r solve for v v T = 2 pi r T = 2 pi r/v
*April 29, 2014*

**history**

http://www.ers.usda.gov/data-products/farm-income-and-wealth-statistics/ranking-net-value-and-farm-income.aspx
*April 29, 2014*

**math**

The dimensions are divisible by 6 except 15 so the cubes will fit exactly on the bottom area of 30*18 = 6*6 *15 so 15 cubes covers 30*18 now it can only be 2 cubes high because of the 15 inch height limitation so 15*2 = 30 cubes
*April 29, 2014*

**calculus**

Hey, this is getting a little silly.6x+30 = 6 (x+5) and 3 (x^2-25) = 3 (x+5)(x-5) I think you better forget the calculus and work on basic factoring.
*April 29, 2014*

**calculus**

(x-3) cancels top and bottom
*April 29, 2014*

**calculus**

I am sure you mean (x^2-1)/(5x+5 ) again factor x+1 cancels
*April 29, 2014*

**Information Literacy**

Building Design 27 July 2012 Note: It is real: http://www.bdonline.co.uk/buildings/london-2012-olympic-park/5040360.article
*April 29, 2014*

**Algebra**

x^2 + (x+4)^2 = 18^2 = 324 2 x^2 + 8 x + 16 = 324 2 x^2 + 8 x - 308 = 0 x^2 + 4 x -154 = 0 x = [ -4 +/- sqrt (16 + 616)]/2 = [-4 +/- 2 sqrt 158 ] /2 = -2 +/- sqrt 158 use + root 10.57 14.57
*April 29, 2014*

**maths**

I do not know any trick, sorry 9.45 * 10^12
*April 29, 2014*

**physics**

m g = 1500* 9.81 m g sin theta = 1500 * 9.81 * sin 2 = 514 N propulsive force Power = force * speed = 514 N * 20 m/s = 10.27 KW
*April 29, 2014*

**precalc**

arrgh, English units :( r = (11/12) ft 2 pi r = 5.76 ft/revolution 600 revolutions/min * 60 min/hr =36,000 rev/hr 36,000 rev/hr * 5.76 ft/rev = 207,360 ft/hr 207,360 ft/hr * 1 mile/5280 ft = 39.3 miles/hr
*April 29, 2014*

**precalc**

45 * 2 pi radians/min = omega v = omega r v = 45*2 pi * 16
*April 29, 2014*

**precalc**

(35 +30) * pi/180 radians times r = distance
*April 29, 2014*

**precalc**

Now wait a minute. You can look this up in your text or sketch it out on paper. There is no need to ask me. for example area of sector = (angle/2pi)area of circle I am sure you can do that isoceles triangle in there push down clutch, engage gears :)
*April 29, 2014*

**Math**

5/1.25 = x/6 x = 30/1.25
*April 29, 2014*

**chemistry**

If it is BASIC, it has an H+ concentration LESS than 10^-7 This is an acid !
*April 29, 2014*

**math**

g / (g/hr) ---> hr
*April 29, 2014*

**math**

gallons per hour hours time = total gallons / rate in gallons per hour
*April 29, 2014*

**phisics - no problem/ no copy and paste**

You can not copy and paste here
*April 29, 2014*

**math**

V = pi r^2 h = pi (4)(9) = 113 s^3 = 113 s = 4.84 cm
*April 28, 2014*

**Algebra**

2*2*2 = 8
*April 28, 2014*

**Algebra**

i = .089/2 = .0445 X = 35,000 (1.0445)^(2t)
*April 28, 2014*

**College Algebra**

w = c L^3 w = c [512] [ (1-e^-t)^3 ] = 512 c ----------- aside multiplication problem (1-e^-t)^3 = (1-e^-t)(1 - 2e^-t +e^-2t) =1(1 - 2e^-t +e^-2t) -e^-t(1 - 2e^-t +e^-2t) = 1 - 2e^-t +e^-2t -e^-t +2e^-2t -e^-3t = 1 -3e^-t +3e^-2t -e^-3t ------------------ w = 512 c [1 -3e^-t +...
*April 28, 2014*

**MATH 12**

4 s h + s^2 = 12 so h = (12-s^2)/4s v = s^2 h v = s^2 (12-s^2)/4s = (12 s^2 -s^4)/4s v = 3 s -(1/4) s^3 dv/ds = 0 for max = 3 - (3/4) s^2 (3/4) s^2 = 3 s^2 = 4 s = 2 h = (12 - 4)/8 = 1
*April 28, 2014*

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