# What is the amplitude, period and the phase shift of y=cos2x?

Mar 29, 2018

Amplitude is 1
Period is halved and is now $\pi$
No phase shift has happened

#### Explanation:

$A \sin \left(B \left(x - C\right)\right) + D$

A~Vertical stretch (Amplitude)
B~Horizontal stretch (period)
C~Horizontal translation (phase shift)
D~Vertical translation

So the A is 1 which means the amplitude is 1
So the B is 2 which means the period is halved so it is $\pi$
So the C is 0 which means it hasn't been phase shifted
So the D is 0 which means it hasn't been upwards