Cos(0,360) or cos (0,2pi)

Question

I am not understanding the question can someone help?

Answer 1

Cosine is the name of a function, so one can write cos(θ) with theta (or another name for an argument) being expressed EITHER in degrees or RADIANS. 0 degrees = 0 radians; the fact that cosine is a PERIODIC function means that cos 0 = cos 360⁰, i.e. cos 0 = cos(2pi).

 

In fact cos (0+k•2pi) = 1 for k any INTEGER.

 

It is never proper to have TWO arguments, i.e. cos(a,b) is not meaningful regardless of what a and b are.

Answer 2

The first is in units of degree, the second is in units of pi-radian.