Question

cos a = ????????​

Answer 1

Sin a € [-1;1]
a не принадлежит R
cos a = R

Answer 2

The value of the cosine (cos) of an angle "a" depends on the specific angle in question, and it ranges from -1 to 1. To provide a numerical value for cos(a), you would need to know the angle "a" in degrees or radians.

For example:

• If "a" is 0 degrees (0°) or 0 radians (0 rad), then cos(a) = 1.
• If "a" is 90 degrees (90°) or π/2 radians (1.5708 rad), then cos(a) = 0.
• If "a" is 180 degrees (180°) or π radians (3.1416 rad), then cos(a) = -1.

So, please specify the value of "a" in degrees or radians for a more precise answer.