Question

Which of the following is the graph of f(x) = cos(x +x++)?

Answer 1

ANSWER:

STEP-BY-STEP EXPLANATION:

We have the following function:

$\: f\mleft(x\mright)\: =\: cos\mleft(x\: +\frac{\pi}{\:2}\mright)$

To know the value in 0, we replace:

$\: f\mleft(0\mright)\: =\: cos\mleft(0+\frac{\pi}{\:2}\mright)=\cos \mleft(\frac{\pi}{\:2}\mright)=0$

Therefore, the possible options would be B and C, but the correct answer is C, since in the sine function the cosine value has been decreasing beforehand.