Question

y=2cos(2pix)

Answer 1

Find the amplitude, period, phase shift, and vertical translation

Answer 2

I believe the answers are:
a. 1
b. ?
c. ?
d. n/a

Answer 3

I meant amplitude is 2

Answer 4

so u dont know b and c yet??

Answer 5

right

Answer 6

the period and the phase shift

Answer 7

ok

Answer 8

Okay... let's be general :)
Say we have this function (NOTE, this can be either sine or cosine, but for our purposes, let's pick cosine)
\[\huge a \ \cos(px+q)+r\]

Answer 9

Assuming p is positive,

Then your amplitude is given by\[\large |a|\]
The period is \[\large \frac{2\pi}{p}\]
The phase shift is\[\large \left|\frac{q}p\right|\]to the left is q is positive, to the right, otherwise...

And finally, the vertical shift is \[\large r\]

Answer 10

so since there isn't a "q" in the equation, then the phase shift is just 2pi ?

Answer 11

The phase shift IS technically 2pi, but your logic in getting there was rather shaky :D
Besides, there IS a q, its value is 0 ;)

Answer 12

Also, a phase shift of 2pi? Remember that cosine repeats itself after 2pi, so a phase shift of 2pi, is like no phase shift at all :D