Question

What is the equation of the graph below?

Answer 1

Explanation:

the equation of the graph : y = sin(x + 90°)

because when : x= 0 : y = sin90° = 1

Answer 2

Option A y = sin ( x + 90 )

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-(-1))/(2)` =
`(2)/(2)` = 1

Since period of the wave is 2x or 360°.

we know, period =
`(2\pi )/(b)`

`b=(2\pi )/(2\pi )` = 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.