Question

(a) What is the exact value of cos 510˚

Answer 1

The answer to your question is cos 510 = -
`(√(3))/(2)`

Explanation:

Data

cos 510° = ?

Process

1.- Find an equivalent angle to 510° subtracting 360°

510 - 360 = 150°

That means that if we calculate the cos 150 will be the same as cos 510

2.- Calculate the cos 150°

150° is located in the second quadrangle. In this quadrangle cosine is negative.

Also, cos 150° = 180° - 30°

If we calculate the cosine of angle 30° will be the same value of cos 150° and the same of cos 510° but with negative sign.

cos 30° =
`(√(3))/(2)` cos 150° =
`- (√(3))/(2)` and cos 510° =
`- (√(3))/(2)`