# How do you graph f(x) = 4 cos(x - pi/2 ) + 1?

Jul 16, 2018

As below.

#### Explanation:

Standard form of a cosine function is $f \left(x\right) = A \cos \left(B x - C\right) + D$

$\text{Given : } f \left(x\right) = 4 \cos \left(x - \frac{\pi}{2}\right) + 1$

$A = 4 , B = 1 , C = \frac{\pi}{2} , D = 1$

$\text{Amplitude } = | A | = 4$

$\text{Period } = \frac{2 \pi}{|} B | = 2 \pi$

$\text{Phase Shift " = -C / B = -(pi/2) / 1 = -pi/2, color(red)(pi/2 " to the LEFT}$

$\text{Vertical Shift } = D = 1$

graph{4 cos(x - pi/2) + 1 [-10, 10, -5, 5]}