CUET Preparation Today
CUET
-- Mathematics - Section B1
Inverse Trigonometric Functions
If tan−12x+tan−13x=π4, then value of x is :
1
14
-1
16
The correct answer is Option (4) → 16
tan−12x+tan−13x=π4
⇒tan−12x+3x1−6x2=π4
so 5x1−6x2⇒5x=1−6x2
6x2+5x−1=0
6x2+6x−x−1=0
6x(x+1)−(x+1)=0
x=16 as x=−1 doesn't satisfy original equation