Question

Which angle is an x–intercept for the function y=cos(1/2x)? A. 0 B. pie/2 C. pie D. 2pie

Answer 1

x intercept is 180

Explanation:

Given

`y = cos((1)/(2)x)`

Required

Determine the x intercept

To do this, we simply set y to 0.

i.e. y = 0

Substitute 0 for y in
`y = cos((1)/(2)x)`

`0 = cos((1)/(2)x)`

Take
`cos^(-1)` of both sides

`cos^(-1)(0) = cos^(-1)(cos((1)/(2)x))`

`90 = (1)/(2)x`

Multiply both sides by 2

`2 * 90 = (1)/(2)x * 2`

`2 * 90 = x`

`180 = x`

`x = 180`

Hence, the x intercept is 180