ANSWER:
STEP-BY-STEP EXPLANATION:
We have the following function:
[tex]\: f\mleft(x\mright)\: =\: cos\mleft(x\: +\frac{\pi}{\:2}\mright)[/tex]
To know the value in 0, we replace:
[tex]\: f\mleft(0\mright)\: =\: cos\mleft(0+\frac{\pi}{\:2}\mright)=\cos \mleft(\frac{\pi}{\:2}\mright)=0[/tex]
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.
