Question

What is the relationship between cos(90degrees) and cos(-90°)? ​

Answer 1

Answer:

The relationship between the two is that they are equal.

Step-by-step explanation:

Since y = cosx is a even function, that means that cosx = cos(-x). Therefore, cos 90 degrees = cos -90 degrees.

We can also test this out:

cos 90 = 0

cos -90 = cos 270 = 0

Therefore, this came to the same conclusion as our first solution.

I hope this helps! :)