Question

.

Answer 1

Well, you know the rule, \(\Large\color{black}{ \bf sin(A+\frac{π}{2})=cos(A) }\) and so it is on the graph,

(knowing that \(\Large\color{black}{ \bf f(x)=2(x+c) }\) ) is c units shifted left from

\(\Large\color{black}{ \bf f(x)=2x }\)

Do you know what I am saying ?

Answer 2

Looking at the graphs you can see this shift.

http://www.wolframalpha.com/input/?i=sin%28x%29
http://www.wolframalpha.com/input/?i=cos%28x%29