Question

cos (5pi) step by step

Answer 1

Sure.

5pi=900 degrees

(remember that pi=180)

900 degrees to put on a unit circle....that makes it a positive 180 degrees.

(view attachment)

recall that a unit circle always has a radius of 1.

therefore the point of intersection for 180 degrees is -1,0.

when a angle is directly on the axis, it is a quadrantal angle.

just remember that cos=x
sin=y
tan=y/x

is the point of intersection is -1,0 and cos=x, what is x?

Answer 2

@Nnesha

check please

Answer 3

yep right but now some people might be ask this question
how did you get 900??

Answer 4

i explained on first 2 line lol

Answer 5

yeah i know but the easy way (i guess for me)
is to subtract 2pi until we get pi that is on the unit circle
:D :P