# Question #a9636

##### 2 Answers

Dec 14, 2016

Dec 14, 2016

#### Explanation:

Reminder:

cos x = cos a -->

Note: the equation can be written in radian form -->

Solve:

cos (2x + 1) = cos (2x - 1)

a. 2x + 1 = 2x - 1 + 2kpi

Equation insolvable

b. 2x + 1 = - 2x + 1 + 2kpi