Evaluate: tan^2 (x) - 3tan (x) + 2 = 0

Let u be the value of tan (x) and that the equation above may also be written as,

u² - 3u + 2 = 0

The equation can be factored as follows,

(u - 1) (u - 2) = 0

u - 1 = 0; u = 1 and u - 2 = 0; u = 2

Thus, tangent (x) = 1 and tangent (x) = 2. The values of x are 45° and 63.43°.