How do you solve Tan^2(x)-|Sec(x)|=1 ?

1 Answer
Nov 30, 2016

x= 2kpi+-pi/3 and

x= 2kpi+-2/3pi, k = 0, +-1, +-2, +-3, ..

Explanation:

|sec x| >=0.

As tan^2x = sec^2x-1 =|sec x|^2-1.

the given equation becomes a quadratic in |sec x|.

|sec x|^2-|sec x|-2=(|sec x|-2)(|xec x|+1)=0.

So, |sec x|=2 to sec x = +- 2

sec^(-1)(+-2)= pi/3 and 2/3pi.. And so,

x= 2kpi+-pi/3 and

x= 2kpi+-2/3pi, k = 0, +-1, +-2, +-3, ..