Question

PLEASE HELP (100 POINTS)

Answer 1

Answer:

I think the third answer.

Hope it can help you.

Answer 2

$\\ \rm\Rrightarrow f(x)=-5cos\dfrac{x}{2}+5$

Compare to standard equation of SHM

$\\ \rm\Rrightarrow y=Acos(\omega x+\phi)$

Here

• Amplitude=A=-5

$\\ \rm\Rrightarrow \omega x=\dfrac{x}{2}$

$\\ \rm\Rrightarrow \omega=1/2$

Well the above one are for extra knowledge .

Solution:-

$\\ \rm\Rrightarrow 10=-5cos\dfrac{x}{2}+5$

$\\ \rm\Rrightarrow 10-5=-5cos\dfrac{x}{2}$

$\\ \rm\Rrightarrow 5=-5cos\dfrac{x}{2}$

$\\ \rm\Rrightarrow cos\dfrac{x}{2}=-1$

$\\ \rm\Rrightarrow \dfrac{x}{2}=cos^{-1}(-1)$

$\\ \rm\Rrightarrow \dfrac{x}{2}=\pi$

$\\ \rm\Rrightarrow x=2\pi$

So.

$\\ \rm\Rrightarrow x=2\pi+2\pi n$