Question

help!

Find the phase shift of the function y = 5cos(2x +pi/2 ).


left pi/2 <<< i chose this!
right pi/2
left pi/4
right pi/4

Answer 1

it is
\[
\frac \pi 4
\]

Answer 2

how come??

Answer 3

factor the argument of your trig function

Answer 4

cos( x+a) has phase a
cos(2 x + a) has phase a/2

Answer 5

match your equation to
\[ A \cos\left( \omega(x + \phi)\right) \]
to make your equation look like that, you must factor a 2 from
(2x + pi/2)
to do this write it as (2x + 2/2 * pi/2)
now factor out 2: 2(x+½ pi/2) or 2(x+ pi/4)