# Find the number of solutions of equation: (1-tan θ)(1+tan θ) sec²θ+2^(tan²θ)=0 when θ∈(-π/2,π/2)?

##### 1 Answer

#### Answer:

..

#### Explanation:

Use

The equation becomes the cubic

Solving this quadratic in

graph{y - x^4 + 2 x^2 +1 = 0[-2 2 -0.01 0.01]}

Sometimes, oversight miss produces good results !

What follows is the solution for mistaken equation

Graph locates only one real root x = - 2.75, nearly.

Astute scaling nearby, approximates x to 5-sd

graph{y-x^3-3x^2-x-1=0}

graph{y-x^3-3x^2-x-1=0[-2.7695 -2.769 -.01 .01]}