Question

graph the function y=3cos(x+pi/2)
to draw the graph, plot all x-intercepts, minima, and maxima within one period.

Answer 1

ok so one period is
\[2\pi\] becuase adding
\[\frac{\pi}{2}\] doe not change the period

Answer 2

can you graph it like it asks? please:)

Answer 3

sure, but first, you should know that the amplitude is 3, because of the 3 out front.

Answer 4

it might also help to know that
\[\cos(x+\frac{\pi}{2})=-\sin(x)\] so this is going to look just like
\[-3\sin(x)\]

Answer 5

if i was going to do this by hand, since the period is
\[2\pi\] i would plot the points where x i s
\[0,\frac{\pi}{2}, \pi, \frac{3\pi}{2}, 2\pi\]

Answer 6

if x = 0 you get
\[3\cos(0+\frac{\pi}{2})=3\cos(\frac{\pi}{2})=0\] so we know we start at (0, 0)
then
\[3\cos(\frac{\pi}{2}+\frac{\pi}{2})=3\cos(\pi)=-3\] so we know we are headed down

Answer 7

then to be brief, back to zero and then up to 3, and then we repeat.
it will look like this
http://www.wolframalpha.com/input/?i=3cos%28x%2Bpi%2F2%29

Answer 8

thank you

Answer 9

yw