Question

Math question

Answer 1

@Michele_Laino Is it D?

Answer 2

your graph is the graph of this function:
\[\Large f\left( x \right) = 2\cos x\]

Answer 3

now, keep in mind that:
\[\Large \begin{gathered}
\sin \left( {x - \frac{\pi }{2}} \right) = \sin x\cos \left( {\frac{\pi }{2}} \right) - \cos x\sin \left( {\frac{\pi }{2}} \right) = \hfill \\
\hfill \\
= - \cos x \hfill \\
\end{gathered} \]

Answer 4

hint:
\[ \Large - 2\sin \left( {x - \frac{\pi }{2}} \right) = 2\cos x\]
so, what is the right option

Answer 5

-cos x so that means it has be to be C?

Answer 6

are you sure? Please follow my last hint

Answer 7

Oh B?

Answer 8

yes! That's right!

Answer 9

Thank you, Michele!

Answer 10

thanks!