Answer:
Option A y = sin ( x + 90 )
Step-by-step explanation:
The given graph is the graph of cosine which should be in the form of
y = a cos ( bx + c ) + d
here a = amplitude =
=
= 1
Since period of the wave is 2x or 360°.
we know, period = ![\frac{2\pi }{b}](https://tex.z-dn.net/?f=%5Cfrac%7B2%5Cpi%20%7D%7Bb%7D)
= 1
Now equation becomes,
y = cos ( x + c ) + d
In this graph there is no horizontal or vertical shift
c = 0 and d = 0
so equation will be y = cos (x)
as we know y = cos (x) = sin ( 90 + x )
Therefore, Option A y = sin ( x + 90 ) is the answer.