Question

What is the domain and range of y = cosx?

Answer 1

@SmokeyBrown

Answer 2

Here's an example of a standard =cos(x) function

https://www.geogebra.org/m/nU2wg2dA

Note that the pattern does repeat indefinitely to the right and left

Answer 3

Actually, that's not a very good example. That's a cosine function shifted to the left.

Answer 4

Here's a better example of a standard cosine function

Answer 5

so domain wold be zero>

Answer 6

Not quite, no. Remember domain refers to the area from left to right that a curve covers. In the case of a cosine curve, it covers all values of x, from negative infinity to positive infinity. So, the domain, as weird as it sounds, is negative infinity to positive infinity

Answer 7

domain = all real numbers

Answer 8

and range is -1

Answer 9

Yup, very well stated. The domain is indeed all real numbers.
For the range, you are half right. The function does go as low as -1, but it also goes as high as +1. The range should include both these values

Answer 10

so range is -1 and 1

Answer 11

Yup, exactly.