Question

use the fact that the trigonometric functions are periodic to find the exact value of the given expression. do not use a calculator. tan 420

Answer 1

The key, jkaitb, is to determine the period of the tangent function. Once that is known you can "unroll" the 420 degrees by repeatedly subtracting the period of the tangent function.

Answer 2

i don't understand

Answer 3

Think about the sin function (it repeats every 2*pi or 360 degrees). So if I asked you what the sin of 420 degrees was... I would subtract (more than once if necessary) 360 degrees from the value.

420-360 = 60 degrees.

So, the sin of 420 degrees is exactly the same as the sin of 60 degrees.