Question

What is (are) the x-intercept(s) of the graph of y = cos x

Answer 1

x intercept would be let y = 0

cos(x) = 0

which degree does cos x equal 0?

Answer 2

well i have these to chose from A. 0, 45, 90, 135, ...
B. 0, 90, 180, 270, ...
C. -90, 90, 270, 450, ...
D. -180, 0, 180, ...

Answer 3

do you have a calculator?

Answer 4

yes a simple regular one does that work

Answer 5

does it have cosine?

Answer 6

it has a button that says cos

Answer 7

does it say \(\cos^{-1}\) somewhere near it?

Answer 8

no

Answer 9

well basically the point is finding degrees where cosx = 0

if you know your unit circle...you know that

cos 0 = 1
cos 90 = 0
cos 180 = -1
cos 270 = 0

so the angles where cosx = 0 would be 90 and 270

Answer 10

to find the other angles subtract 180 from 90 then add 180 to 270 so that gives you

-90, 90, 270 , 450

Answer 11

thanks (: