Thursday

September 3, 2015
Total # Posts: 21,879

**Math**

13% is so much more than 6% that the compounding will not catch up for many years.
*June 10, 2015*

**Math**

1.06^4 = 1.26248 *2000 = 2524.95 so earned 524.95 0.13 * 4 =.52 .52 * 2000 = 1040 so earned 1040.00 go with the 13 % simple
*June 10, 2015*

**Chemistry**

how many Joules do you need? Joules needed = specific heat * mass * change in temp then watts * seconds = Joules needed
*June 9, 2015*

**Chemistry**

C * m (60-40) = C * 50 (40-20) so m = 50 grams or .050 Kg
*June 9, 2015*

**History**

Should I laugh or cry?
*June 9, 2015*

**Calc 1**

sure looks like it to me
*June 9, 2015*

**Calc 1**

Hey, you can google too :)
*June 9, 2015*

**Calc 1**

not necessarily http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&cad=rja&uact=8&ved=0CEgQFjAI&url=http%3A%2F%2Fwww.mathsisfun.com%2Fcalculus%2Fdifferentiable.html&ei=2wt3VbzLIMGasQXEoIEI&usg=AFQjCNG-Oqx8EjGrCBl7-c8WA0YYFZ28ag&sig2=WquSfxU_It3cBOBGKCGExg&bvm=bv....
*June 9, 2015*

**Calc 1**

True, if more then not a function http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CDMQFjAC&url=http%3A%2F%2Fwww.milefoot.com%2Fmath%2Fcalculus%2Flimits%2FFindingAsymptotes12.htm&ei=ZAt3Ve-jC4mQsAXlt4HgDQ&usg=AFQjCNHZjboUch1fdELGYXBuIZC-Tnu_rg...
*June 9, 2015*

**Calculus 1**

well, if x = .99 I get 1.50 if x = .999 then 1.500 that is because numerator = (x-1)(x+2) denominator = (x-1)(x+1) so what we really have is (x+2)/(x+1) which is 1.5 at x = 1 It is true that the original function is undefined at x = 1
*June 9, 2015*

**physics**

They are brakes. after 5 sec at constant v Vi = 20 v = 20 + a t where t is total time - 5 v = 0 when t = 8 so 0 = 20 + a (8) a = -20/8 = - 5/2 so v = 20 - (5/2) t = 20 - (5/2)(time - 5)
*June 9, 2015*

**Math**

11 with vanilla + 11 with chocolate = 22 , right
*June 9, 2015*

**Calc 1**

y at x = 5 = a then y^2 = 25 all right when x = 5
*June 9, 2015*

**math**

total N = 330 + 900 = 1230 Total E = 640 + 370 = 1010 so sqrt (1230^2 + 1010^2)
*June 9, 2015*

**Calc 1**

nope, what if y = L (x-a)/|x-a|
*June 9, 2015*

**Math**

pi is actually about 22/7 This problem is a lot harder than it looks because you should really pack the discs in a hexagonal pattern but I suspect the best we can do is put squares around the circles. 100 /14 = 7.14 so 7 lengthwise 60/14 = 4.28 so 4 that direction 7 * 4 = 28 ...
*June 9, 2015*

**math trigonometry**

I have no reason to believe it is true.
*June 9, 2015*

**SCIENCE**

A to B speed = 300m/170 seconds velocity = speed if that direction is + then A to C distance = 300 + 100 = 400 average speed = 400/230 but total displacement = +300 - 100 = 200 so'=average velocity = 200/230
*June 9, 2015*

**math**

I do not think so. Sketch a graph.
*June 8, 2015*

**Physics**

x = 1.40 t^2 - .0505 t^3 at t = 0, x = 0 at t = 1.91, x =1.40 * 1.91^2 - .0505 * 1.91^3 = 4.755 meters so 4.755 meters in 1.91 seconds = 2.5 m/s do the others the same way, find out how far it went in the time interval and divide by the time interval
*June 8, 2015*

**statistics**

5/15 * 4/14
*June 8, 2015*

**MATH**

x/10 = 37/8 so x = 370/8 (370/8)/16 = 370/128 = 2 114/128 = 2 57/64
*June 8, 2015*

**math**

2* (1/2) pi (1) + 2*3 maybe ?
*June 8, 2015*

**Math help please.**

7 yes 8 A because -3 * -2 = +6
*June 8, 2015*

**Math help please.**

6)-2r(8r+5) A)-16r^2+5 B)-16r+10 C)-16r-10r** D)-16r-10 Nah, -16 r^2 - 10 r probably c but a typo
*June 8, 2015*

**Math help please.**

7^4/7^2 = 7^2 = 7*7 = 49 right
*June 8, 2015*

**Math help please.**

4) 50 A)0 B)5 C)1 D)-5 Perhaps you mean 5^0 but anything^0 = 1
*June 8, 2015*

**Math help please.**

3) 4^4/4^6 4 - 6 = -2 4^-2 = 1/4^2 = 1/16 A)-16 B)16 C)1/16 D)-1/16
*June 8, 2015*

**Math help please.**

2) h^14/h^5 14 - 5 = 9, not 19
*June 8, 2015*

**Math help please.**

1) x^9/x^2 = x(9-2) = x^7
*June 8, 2015*

**maths**

if the second hand moves 180 degrees, that is half a minute .5 min (360 degrees/60 min) = 3 degrees
*June 8, 2015*

**Calculus**

Oh, go with what Steve said.
*June 8, 2015*

**Calculus**

profit = p(x) - C(x) = 50-.01 x - 10 - 2x = 40-2.01 x max at x = 0 I bet you have a typo though.
*June 8, 2015*

**math**

well one way is a parabola write a parabola that goes through (4,1) (6,1.5) and (8,6) first (4,3) (6,0) and (8,0) Y1 = 3(x-6)(x-8) /(4-6)(4-8) = 3(x^2 -14 x + 48)/ 8 second (4,0)(6,1.5)(8,0) Y2 = 1.5 (x-4)(x-8)/(6-4)(6-8) = -(1.5 x^2 -18 x +48)/4 third Y3 = 6(x-4)(x-6)/(8-4)(8...
*June 7, 2015*

**math**

whoops, I dd it for 300 of fence, not 200
*June 7, 2015*

**math**

if two internal petitions the 4 x needed for cross fencing + 2 L needed for length P = 4 x + 2 L =300 or L = 150 - 2 x A = x L = x (150 - 2 x) = 150 x - 2 x^2 if you know calculus: dA/dx = 0 at max = 150 - 4 x so x = 150/4 = 37.5 then L = 150 -2*37.5 = 75 AREA = 37.5*75 = 2812...
*June 7, 2015*

**COLLEGE MATH**

I do not know what level of math you are at. If calculus then dC/dx = 0 at min = .4 x =96 so x = 240 If Algebra 2 level then complete the square to find vertex .2 x^2 - 96 x = -12095 x^2 - 480 x + 240^2 = - 60475 x^2 - 480 x + 240^2 = - 2875 (x-240)^2 = -2875 so x = 240 and C...
*June 7, 2015*

**Another math related question**

4/10 * 7/15 = 14/75
*June 7, 2015*

**Calculus**

you have P = 2 x + 154/x BUT you took the derivative incorrectly P' = 2 -154/x^2 so for min or max 0 = 2 - 154/x^2 or x^2 = 77 NOTE d/dx (1/x) = -1/x^2
*June 7, 2015*

**physics**

any acceleration is down the slope, perpendicular to the force we are interested in. That normal force is the component of weight normal to the hill surface which is m g cos 25
*June 7, 2015*

**physics**

If two capacitors are in parallel, they hold more charge for a given voltage. We know that C = Q/V here C1 = Q1/V C2 = C2/V C1 + C2 = (Q1+Q2)/V so final C = C1 + C2 In other words, if in parallel, add capacitances because you add charges per unit voltage
*June 7, 2015*

**to damon**

You are welcome - good luck !
*June 7, 2015*

**algebra**

ah ham you know Pascal's triangle so you know binomial theorem after all now call a = 4 y call b = x then (a+b)^4 = a^4 + 4 a^3b + 6 a^2b^2 + 4 a b^3 + b^4 which is 256 y^4 + 256x +6 (4y)^2 x^2 etc
*June 7, 2015*

**maths**

sin PQR = 300/600 = 1/2 so PQR = 30 degrees that is 30 degrees south of west or 60 degrees west of south which id a compass bearing of 180 + 60 = 240 degrees clockwise from north cos 30 = RQ/600 RQ = 520 m
*June 7, 2015*

**algebra**

no imagine (x-y)^2 it is not x^2 - y^2 but x^2 - 2 x y + y^2 You need the "binomial theorem" If you have learned it your problem is straightforward, follow the recipe. If you have not had it in your course, I feel for you because you will have to do it step by ...
*June 7, 2015*

**algebra**

(x^4 y^5)^5 = (x^4)^5 (y^5)^5 = x^20 y^25
*June 6, 2015*

**Physics**

do the fall first v = g t 44 = 9.81 t t = 4.49 seconds falling now the up part Vi = 24.4 v = Vi - g t 0 = 24.4 - 9.81 t where t is time rising t = 2.49 seconds upward so 4.49 + 2.49 seconds
*June 6, 2015*

**Physics**

Yes, your wording indicates that you need help. You not only have to heat the water to 100 deg C You have to BOIL IT as well ! so look up the specific heat of water, call it C then LOOK UP THE HEAT OF VAPORIZATION of water. then heat in = 2 * specifc heat * (100-37) + 2 * heat...
*June 5, 2015*

**6th Grade Probability**

1/4 of the times you play (1/4)36 = 9
*June 5, 2015*

**Physics**

wavelength = twice string length to get node at each end and bulge in middle. L = (1/2) wavelength wavelength = speed * period = speed/frequency so L = (1/2) v/f
*June 4, 2015*

**Algebra**

check below http://www.jiskha.com/display.cgi?id=1433381900
*June 4, 2015*

**Physics**

You are welcome.
*June 4, 2015*

**Physics**

The tension and mass density determine the speed of the wave along the string. The input frequency is the wave frequency wavelength = speed * period = speed/frequency so frequency, tension and mass density right
*June 4, 2015*

**Physics**

A yes B yes C No D yes I agree.
*June 4, 2015*

**Algebra**

L^2 + w^2 = d^2 (d-3)^2 + (d-8)^2 = d^2 d^2 - 6 d + 9 + d^2 -16 d + 64 = d^2 d^2 - 22 d + 73 = 0 d = [ 22 +/- sqrt(484 - 292) ] / 2 d = [ 22 +/- 13.9 ] / 2 d = 17.9 or 8.1 8.1 is impossible if the area is 84 so d = 17.9 ------------------- check then w = about 10 and L = about...
*June 4, 2015*

**Math**

66 = 2*33 = 2 * 3 * 11 99 = 3 * 33 = 3 * 3 * 11 20 = 2*10 = 2 * 2 * 5 etc, boring
*June 4, 2015*

**Math**

look at b^2 - 4 a c if +, then two intercepts if 0, then just grazes the x axis, one intercept if -, then never hits the axis, imaginary roots only if a x^2 + b x + c = 0 then - (a x^2 + b x + c) = 0 is the same because +0 = -0
*June 4, 2015*

**math**

sin^4x-cos^4x = (sin^2 x+cos^2 x)(sin^2 x -cos^2 x = 1 (sin^2 x - cos^2 x) = 2 sin^2 x - 1
*June 4, 2015*

**physics**

d1 = (1/2)(5)(64) Vi = 0 + 5 * 8 d2 = Vi * (12-8) d = d1 + d2
*June 4, 2015*

**math**

one leg of right triangle is 150 other leg is 120 sqrt (150^2+120^2) = 192
*June 3, 2015*

**Social Studies**

You are welcome.
*June 3, 2015*

**Social Studies**

Write your thoughts and perhaps a teacher will help. hints - where is the Statue of Liberty ? What words are on it? How many buffalo are around, not to mention native tribes ? Wicked difficult growing cotton and rice and stuff under the snow.
*June 3, 2015*

**Math**

slope = (13-10)/(5-4) for example = 3 so T = = 3 S + b 1 = 3 + b b = -2 so T = 3 S - 2
*June 3, 2015*

**Math**

sorry - I used 15 mph instead of 18
*June 3, 2015*

**Math**

at 12 it tskes t so d = 12 t at 15 it will take .25 leas time d = 15 (t-.25) so 12 t = 15 t - 15/4 3 t = 15/4 t = 5/4 d = 12(5/4) = 15 miles
*June 3, 2015*

**Math**

120 = x t so t = 120/x 120 = (x+5)(t-1/3) or 120 = (x+5)(120/x - 1/3) 120 (3)(x) = (x+5)(360 - x) 360 x = 360 x -x^2 + 1800 -5 x x^2 + 5 x - 1800 = 0 (x-40)(x+45) = 0 x = 40
*June 3, 2015*

**Math**

t is time after 12 noon f for freight train distance f = df = 50 t p for passenger train dp = 60 (t-1) when is dp - df = 300 ? 60(t-1) - 50 t = 380 10 t - 60 = 380 10 t = 440 t = 44 hours so one day and 20 hours so 8 am --------------------------------- total distance = 2d ...
*June 3, 2015*

**physics**

120/360 = 1/3 of circumference so distance pushed = d = (1/3) 2 pi (.9) work = force * d = 11 *d Joules power = work/time = 11 * d / 2.2 in Watts
*June 3, 2015*

**PHYSICS**

v = a t where a = alpha = angular acceleration = torque/I here I is moment of inertia of uniform disc = (1/2) m r^2 so I = (1/2)(6)(.04) = .12 and a = 30/.12 = 250 radians/s^2 then v = 250 t and theta = (1/2)a t^2 = 4 pi radians so 125 t^2 = 4 pi t = .317 second then v = 250(....
*June 3, 2015*

**math**

3 x^2 - 12 x - 7 = 0 x = [ 12 +/- sqrt(144+84) ] / 6 = [ 12 +/- sqrt(228) ] / 6 = [ 12 +/- 2 sqrt(57) / 6 = [ 6 +/- sqrt(57) ] / 3 Use PARENTHESES !!!~!!~!!!!! I can not tell whsat is your numerator.
*June 3, 2015*

**civics**

Looks pretty federal to me.
*June 3, 2015*

**civics**

yes
*June 3, 2015*

**civics**

Well which do you think based on the answer to your other question?
*June 3, 2015*

**math**

0 = 1^2 - 1 3 = 2^2 - 1 8 = 3^2 - 1 15= 4^2 - 1 25= 5^2 - 1 Term = n^2 - 1
*June 3, 2015*

**Physics**

As far as I know a right hand rule is a right hand rule.
*June 3, 2015*

**physics**

first get acceleration of the two masses a = F/m = (2*9.81)/(7) then: mg - T = m a 2*9.81 - T = 2 a T = 2 (9.81 - a)
*June 3, 2015*

**Math**

because if they were similar then if V to W is 5 and R to S is 10 then if similar W to X must be HALF of S to T It is not, it is sqrt 5 times I know which sides to compare because I drew a quick sketch of the two figures.
*June 2, 2015*

**Math**

V to W = sqrt (25+0) = 5 R to S = sqrt (100+0) = 10 W to X =sqrt(49+9) = sqrt(58) S to T = sqrt(169+121) = sqrt (5*58) oh my :(, not twice, would be sqrt 4*58 if similar
*June 2, 2015*

**Math**

agree
*June 2, 2015*

**physics**

m g /area m = .050 KG g = 9.8 m/s^2 area = pi r^2 = pi (9 *10^-6) meters^2 so p = .0173 * 10^6 N/m^2 or Pascals = 1.73 * 10^4 Pascals or around .2 atmospheres
*June 2, 2015*

**physics**

That makes no sense to me at all. The total mechanical energy is the sum of the kinetic and potential energies.
*June 2, 2015*

**Algebra**

t = k/r 12 = k/60 so k = 12*60 then t = 12*60/85 = 8.47
*June 2, 2015*

**Physics**

well, the second equation is -A cos 41.9 + B cos 25.2 = 0 which is B = A(cos 41.9 / cos 25.2) so use that for B in the first equation
*June 2, 2015*

**Physics**

assume if A is in Quadrant 2 then B is in quadrant 1 (or the opposite, does not matter) sum of y components = 0 A sin 41.9 + B sin 25.2 - 25.8 = 0 sum of x components = 0 -A cos 41.9 + B cos 25.2 = 0
*June 2, 2015*

**physics**

d = .8 meter so F = G *55*70 /(.64) where G = 6.67*10^-11 m^3 /(kg s^2)
*June 2, 2015*

**physics**

force = 2*9.81 - 7 = 12.6 Newtons accelerated mass = 5 + 2 = 7 a = F/m = (12.6/7) m/s^2
*June 2, 2015*

**Math**

well, look at what happens to point (-1,0) it remains at (-1,0) when reflected around y=x+1 because it is on that line so just reflect it about y = x+3 drawing the graph I see it went left 2 from -1 and up the same amount, 2, from 0 so left 2 and up 2 :)
*June 2, 2015*

**Math help please**

40/80 = .5 20/80 = .25 60/80 = .75 so steepest 3/4 D
*June 2, 2015*

**Math**

believe me, it is much less confusing using another symbol for x^2 then replacing it at the end.
*June 2, 2015*

**Math**

let f(x) = z = x^2 so x = sqrt z and z always positive y = 3 (-4 sqrt z-2)^2 + 5 y = 3(16 z + 16 sqrt z +4) + 5 y = 48 z + 48 z^.5+ 17 y = 48 f(x) +48 f(x)^.5 + 17
*June 2, 2015*

**Math**

Steve and I both said the same thing in different ways. Here is another. like when is 2x+3 = 0 ??? when x = -3/2 so what is f(0) it is 0 so when x = -3/2 then g(x) = 0
*June 2, 2015*

**Math**

if x = -1, 2x+3 = 1 and -f(1) = -4 if x = 0, 2x+3 = 3 and -f(3) = -10 etc
*June 2, 2015*

**Math**

Huh? If that is a table of values of x and y, then y = 5 when x = 3
*June 2, 2015*

**Physics**

I guess you mean g = 10 m/s^2 Work done = increase in potential = m g * increase in height = 5 kg * 10 m/s^2 * 10 m = 500 Newton meters = 500 Joules
*June 2, 2015*

**Math (check answers)**

5 d^(6-12) = 5 d^-6 yes
*June 1, 2015*

**civics**

I think D is the correct answer. but knowing the speaker, it might be C :)
*June 1, 2015*

**algebra--1 question**

No, read above, a
*May 31, 2015*

**algebra--1 question**

check 14*75 = 1050 300 + 750 = 1050 sure enough
*May 31, 2015*

**algebra--1 question**

x^3+0x^2-7x+6/(x+3) = x^2-3x+2 which is a
*May 31, 2015*

**Algebra II**

agree but check as follows 1 + 5 (6-8) = 2 - (6+5) ???? 1 - 10 = 2 - 11 ??? -9 = - 9 Yes :)
*May 31, 2015*