Wednesday

September 28, 2016
Total # Posts: 44,155

**8th grade math**

The slope-intercept form is called that for a reason: y = 0.2x + 0.3 decimals are just numbers, like any others.

*September 14, 2016*

**Physics**

you want (x,y) such that (11cos67,11sin67) + (x,y) = (7.7cos98,7.7sin98) Evaluate x and y, and then find θ such that tanθ = y/x

*September 14, 2016*

**math**

7 3/4 = 28/4 + 3/4 = 31/4 Now, 7 3/4% is 31/400

*September 14, 2016*

**Math**

foot: x/3.5 = cos70° top: y/3.5 = sin70°

*September 13, 2016*

**Math**

you are correct in a general way. That's true for any ratio.

*September 13, 2016*

**algebra**

1.40x + 0.25 = 1.99

*September 13, 2016*

**Calculus integrals**

well, there's no algebraic way to do it that I know of. Best to check the graph and approximate it. You know that x^2-36 is zero at ±6. cos^2(x) is positive there, so x will be on the inside of the interval (-6,6). So you can check nearby values and approximate it ...

*September 13, 2016*

**Calculus integrals**

well, df/dx = (x^2-36)/2 + cos^2(x) where is that zero? which is a max?

*September 13, 2016*

**math**

no idea. How tall was Tanya at age 6?

*September 13, 2016*

**Math**

If $x is at 4%, the rest $(8000-x) is at 2.5%, so .04x = .025(8000-x) + 34

*September 13, 2016*

**Physics**

2.4t^2 = 409

*September 13, 2016*

**physics**

she's late. avg speed is totaldistance/totaltime distance = speed * time

*September 13, 2016*

**Math**

well, it's √((-2-4)^2+(3+1)^2) = ...

*September 13, 2016*

**Math**

nope

*September 13, 2016*

**math**

m = 3j j/p = 5/2 p = 140 m = 3j = 3(5p/2) = 3(5*140/2) = ?

*September 13, 2016*

**Algebra**

well, what has changed? b and c changed places. Unfortunately, it's called "commutative" not "communicative" I guess you weren't communicating to well when the topic was covered.

*September 13, 2016*

**Geometry**

since PQS is half of PQR, PQR is 90 degrees. QED

*September 13, 2016*

**algebra**

see related questions below

*September 13, 2016*

**algebra**

7/12 * 24M

*September 13, 2016*

**Math**

mean and median will increase by 5 std will not change. Try it. That's the whole point of the std - it is independent of the actual magnitudes, just their spread. Your µ and σ look ok, too.

*September 13, 2016*

**math**

see http://www.jiskha.com/display.cgi?id=1473791919 same problem, different numbers.

*September 13, 2016*

**math**

j:e = 5:2 s:j = 4:9 j=36, so 36:e = 5:2 s:36 = 4:9 = 16:36 so, s=16 Now we have 36:e = 5:2 I don't like that, since 36 is not a multiple of 5.

*September 13, 2016*

**math**

m/e = 3/5 (m-7)/(e+7) = 1/3 Now just solve for m and e.

*September 13, 2016*

**Math**

Hint: 15+8=23

*September 13, 2016*

**math**

you're kidding, right? See Reiny's figures above.

*September 13, 2016*

**Physics**

F=ma plug in your numbers

*September 13, 2016*

**Math**

Assuming I interpret your bizarre language correctly, it appears you want x - 1/2 = 1/8 If I got that wrong, why don't you express your question as math?

*September 13, 2016*

**maths**

224000(1.02^16 - 1)

*September 13, 2016*

**Geometery**

If the length is x, then 2(x-1 + x) = 54

*September 13, 2016*

**algebra**

(14/3)x = 3131 x = 3131 * 3/14 = ? why waste all that time and space describing the fraction instead of writing it? sheesh.

*September 13, 2016*

**algebra**

3(x-2) + 2x = 4(x+2)-77

*September 13, 2016*

**math**

you know that for one cylinder, v = πr^2 h so, plug in your numbers and add .065L (as mm^3)

*September 13, 2016*

**Algebra**

since distance = time * speed, 7(x-y) = 28 4(x+y) = 48

*September 13, 2016*

**Algebra**

well, 7-4 = 3

*September 13, 2016*

**Algebra**

(1/5)x - (1/9)(x+1) = 3

*September 13, 2016*

**differential calculus**

how about v = 120000 * 0.92^t ??

*September 13, 2016*

**Maths**

If this much time has passed with no response, it is usually an indication that no one is sufficiently versed in statistics and probability theory that they feel they can provide useful help. I know that I'd have to review my textbooks to work it out. Believe it or not, we...

*September 13, 2016*

**Physics**

You have 5v + a/2 * 5^2 = 40 10v + a/2 * 10^2 = 105 Now just solve for v.

*September 13, 2016*

**Triangles**

yes

*September 13, 2016*

**Triangles**

13-10 < x < 13+10

*September 13, 2016*

**mathematical phyaics**

using the determinant form, two rows are the same, so the determinant is zero

*September 13, 2016*

**mathematical phyaics**

You have probably already seen that Ax(wxu) = w(A.u)-u(A.w) Now let A = vxw Then (vxw)x(wxu) = w(uxvxw) So, (uxv).(vxw)x(wxu) = (uxv).w(u.vxw) = (uxv.w)(u.vxw) = (u.vxw)^2 There are other proofs online

*September 13, 2016*

**mathematical physics**

a' = i + e^t(t^2+2t)j + 2cos2t k T = a'/|a'|

*September 13, 2016*

**Math**

just solve -16t^2 + 64t + 4 = 6464

*September 13, 2016*

**math**

24 = 2^2 * 3 48 = 2^3 * 3 52 = 2^2 * 13 so, what is the LCM?

*September 13, 2016*

**science,physics**

if moving in opposite directions, 3*5 = 2v

*September 13, 2016*

**MATHS2**

https://answers.yahoo.com/question/index?qid=20061106084200AAifTZM

*September 13, 2016*

**math 101**

.06x + .15*2 = .12(x+2)

*September 13, 2016*

**Math 172**

it's when R(x) = C(x) 23x = 14x+9000 Now just solve for x, then evaluate y.

*September 12, 2016*

**Math**

won't work. You must have balanced parentheses. Hint: 9*2 = 18

*September 12, 2016*

**math**

depends on how many were in the big bag, which you did not say.

*September 12, 2016*

**Math**

(u-5v)x(u+4v) = uxu - 5vxu + 4uxv - 20vxv = 9uxv (why?)

*September 12, 2016*

**math**

time = distance/speed, so t = 50/s

*September 12, 2016*

**Math**

one is a power of 2, one is an odd multiple of 2.

*September 12, 2016*

**Algebra 2**

b = bh/2 - 3 h = bh/2 - 6 bh/2 = b+3 = h+6 so, h = b-3 b = b/2 (b-3) - 3 2b = b^2-3b-6 b^2-5b-6 = 0 b = 6 or -1 pick b=6 so, h=3 bh/2 = 6*3/2 = 9

*September 12, 2016*

**math**

I think you mean difference of squares (3a-4)(3a+4)

*September 12, 2016*

**Calculus**

a = 2i + 6tj + 12t^2k v = 2ti + 3t^2j + 4t^3k + c at t=0, v=i, so c = i and v = (2t+1)i + 3t^2j + 4t^3k r = (t^2+t)i + t^3j + t^4k + c use r(0) to see that c = 2j-7k so r = (t^2+t)i + (t^3+2)j + (t^4-7)k

*September 12, 2016*

**Math**

-8 and -8

*September 12, 2016*

**math**

that already is

*September 12, 2016*

**Calculus**

just use the definitions in your text. Simple derivatives.

*September 12, 2016*

**matematicas**

xxx si, pero no es un ano (hablo portugues)

*September 12, 2016*

**matematicas**

si, mas no es un ano

*September 12, 2016*

**matematicas**

x = ano de mi nacimiento este ano = 1997 x+1997 - (x+10) - (x+15) + (1997-x) = 80 Hmmm. Debo de haber cometido un error. Pero se entiende la idea: poner las palabras en matemáticas

*September 12, 2016*

**math**

9i - 5 - 3i -5 + 6i

*September 12, 2016*

**math**

hint: the i stands for imaginary

*September 12, 2016*

**MATH**

(634/10) * 14 inches

*September 12, 2016*

**math**

numerical expressions

*September 12, 2016*

**Maths**

dilation

*September 12, 2016*

**Solid mensuration**

since the top diameter is 7/12 as big as the bottom diameter, the missing piece has a slant height of (7/5)(13) So to figure the numbers for the frustrum, find them for the entire cone and subtract the value for the missing piece. Or, since the frustrum is 7/19 as high as the ...

*September 12, 2016*

**Math**

the probability of getting any six specific tosses is (1/2)^6

*September 12, 2016*

**algebra**

so, just plug in your numbers!

*September 12, 2016*

**Algebra**

spot on.

*September 12, 2016*

**Calculus**

the density will be the (average value of the population) divided by the area just as we had to integrate the density times area to get total population . Remember that the average value of f(x) in the interval [a,b] is ∫[a,b] f(x) dx ------------------ ...

*September 12, 2016*

**Calculus**

funny how much time google can save you http://www.math.ucla.edu/~ronmiech/Calculus_Problems/32A/chap11/section7/732d51/732_51.html

*September 12, 2016*

**Calculus**

see your text for examples, or http://mathinsight.org/parametrized_curve_tangent_line_examples

*September 12, 2016*

**Math**

#1. Just pick any 6 consecutive integers and try it out #2. Consider the numbers x-2, x-1, x, x+1, x+2 #3. Should be clear. Even if you're not sure about some of them, the right one jumps out. #4. any multiple of 2 is even #5. start by noting that 17 is prime #6. trick ...

*September 12, 2016*

**algebra**

solve for what? And of course, it's probably vt, not ut.

*September 12, 2016*

**algebra**

do the division. If the remainder is subtracted, the new remainder will be zero.

*September 12, 2016*

**SS ICY NORTH**

I see someone else (not you?) was asking about Canada icy north google turned up several references for that

*September 12, 2016*

**SS ICY NORTH**

Hmmm. I see a few hits on google, but they relate to different topics. I see your subject is social studies. What kind of ICY NORTH are you referring to? Climate, Rock Band, what?

*September 12, 2016*

**SS ICY NORTH**

google

*September 12, 2016*

**Physics**

46 mi/hr = 20.56 m/s so v = at means t = 20.56/2.35 s work the other similarly or, just consider the ratio of time lengths

*September 12, 2016*

**profit and loss**

do you mean that If he now gets x eggs for rs10 he would get x+6 eggs or the discount lets him get 6 eggs for rs10?

*September 12, 2016*

**Science**

try this https://www.google.com/#q=inductive+vs+deductive is that your final answer?

*September 12, 2016*

**Calculus**

The population in a ring of radius r is density * area, so adding up all the rings you get ∫[0,7] 6∛(3+r^2) * 2πr dr hint: let u = 3+r^2 for the volume, you can use shells: ∫[0,5] 2πrh dx = ∫[0,5] 2πx(5x-x^2) dx discs: ∫[0,25] π...

*September 12, 2016*

**physics**

https://www.google.com/#q=drift+velocity+area+conductor

*September 12, 2016*

**Algebra2**

well, assuming your = means +, 6x+9y=6 6x-10y=44 ...

*September 12, 2016*

**Math**

f(x) = (1/x)^(sinx) = 1/(x^sinx) Let us take the limit as x→0+, since rasning negative numbers to real powers is not well defined. consider limit x→0 g(x)=x^x lng = x lnx = lnx/(1/x) limit ln g(x) as x→0 = (1/x)/(-1/x^2) = -x limit ln(g(x)) = 0 so, limit g(x...

*September 12, 2016*

**Maths Percentage**

1.4 * ate = 70 ate = 50 what do you get for the other parts? If you get stuck, show how far you got. You must have at least some idea where to start, even if it is only defining a variable.

*September 12, 2016*

**precalculus**

ok. It appears to be in QIV, and is a 12-35-37 right triangle. If you draw it correctly, you should be able just to read off the values of the trig functions of that angle.

*September 12, 2016*

**Maths Percentage**

Syed's is 5/4 of Emraan's So, Emraan's is 4/5 of Syed's

*September 12, 2016*

**Math**

no problem. Feel free to stop by any time, but next time you need to ante up some work before we bother betting.

*September 12, 2016*

**Math**

As written, I get none of the above. Show your work, and we can check what's going on. To get -16, the 2nd term must come out to -32, since 16-32 = -16

*September 12, 2016*

**mechanic**

200^2 + 200^2 - 2*200*200cos(π-θ) = 100 the two forces must be very nearly in opposite directions.

*September 12, 2016*

**science**

120g/6mL = 20g/mL

*September 12, 2016*

**Math**

.10*100 + .20*89 + .55*82 + .15*81 ≈ 85

*September 12, 2016*

**Calculus**

well, I get -114.755 so maybe the key wants -114.76 or -114.8 or -115

*September 12, 2016*

**Calculus**

I think you subtracted wrong. Try (f(4)-f(-5))/9 = -114.75 as a quick look at the graph would indicate: http://www.wolframalpha.com/input/?i=3x%5E3-12x%5E2

*September 12, 2016*

**Calculus**

L'Hospital's Rule: (1/(1+x^2) - 1)/(3x^2) = (-x^2/(1+x^2))/(3x^2) = -1/(3(1+x^2)) -> -1/3

*September 12, 2016*

**Math**

if there are 5x girls and 12x boys, then 17x = 5200 Hmmm. 17 does not divide 5200. Now, if there were 5100 students, then x = 300.

*September 12, 2016*