# How do you find the solution for #cosx - 1/cosx = 5/6# for [-180,180]?

##### 1 Answer

Oct 21, 2015

Solve

Ans:

#### Explanation:

Call cos x = t and solve the quadratic equation for t.

Use the new Transformation Method.

Transformed equation -->

Factor pairs of (-36) --> (-3, 12)(-4, 9). This sum is 5 = -b. Then y1 = -4 and y2 = 9. Therefor, the 2 real roots of equation (1) are:

a.

b.