Question

solving eqautions

Answer 1

http://www.mathsisfun.com/algebra/equations-solving.html

Answer 2

I forgot how to solve for multiple values of t any help is appreciated.



\[v(t)=\frac{ -40 }{ 3 }\cos (\frac{ 3t }{ 2 })-5.129\]

I was able to solve for t when when v(t) = 0 but I am not able to get the other values of t.

Answer 3

@ganeshie8 can you help i forgot this

Answer 4

@aaronq

Answer 5

I'm not sure if I can help.
But this is what I think.

do you have any other values for \(v(t)\)?
because I dont think you can solve for \(t\) if you dont have any values for \(v(t)\).

IF you font have, probably you can substitute any values for \(v(t)\) then solve for t. OR do it the other way. Substitute values for \(t\) to solve for \(v(t)\)

Answer 6

I need all values of t for when v(t)=0 I only got 1 value and I forgot how to get the rest.

Answer 7

oh i see.

\(0=\frac{-40}{3}cos(\frac{3t}{2})-5.129\\5.129=\frac{-40}{3}cos(\frac{3t}{2})\\\frac{3(5.129)}{-40}=cos(\frac{3t}{2})\\-0.384675=cos(\frac{3t}{2})\\cos^{-1}(-0.384675)=\frac{3t}{2}\\2(cos^{-1}(-0.384675))=3t\\t=\frac{2(cos^{-1}(-0.384675))}{3}\)

Answer 8

Yeah that gives me approx. 1.31, but how do I get the rest?

Answer 9

i'm not totally sure because I forgot trig eq.
but i think since after 1 cycle (after \(2 \pi\)), the wave will be at zero again at a different location, so I THINK... you have to add \(2 \pi\) on the value of \(t\) depending on the range of your domain.

Answer 10

I mean \(\frac{\pi}{2}\) not \(2 \pi\)
so for example, I got approx t=75° from before, i'll just have to add 90° to it so the next location will be at 165°.. substitute 165° to check if this gives you \(v(t)=0\)

Answer 11

The cosine looks like this