Question

How do you graph `y=sin(x+pi/2)`?

Answer 1

`y=cos(x)`

Explanation:

`sin(a+b) = sin(a)cos(b) + cos(a)sin(b)`

Hence:
`sin(x+pi/2) = sin(x)cos(pi/2) + cos(x)sin(pi/2)`

`= sinx*0 + cosx*1 =cosx`

`:.` the graph of `y` is the graph of `cosx` as below:

graph{cosx [-6.243, 6.24, -3.12, 3.123]}