AP EAMCET202120 Aug 2021Evening ShiftMathematicsInverse Trigonometric FunctionsActual
tan - 1 ( - 2 ) - tan - 1 ( 3 ) is equal to
Options
- A3 π 4
- B- π 6
- Cπ 6
- D- 3 π 4
Correct answer
D. - 3 π 4
Step-by-step solution
Given that: tan - 1 ( - 2 ) - tan - 1 ( 3 ) As we know that, tan - 1 ( - x ) = - tan - 1 x = - tan - 1 ( 2 ) - tan - 1 ( 3 ) = - ( tan - 1 ( 2 ) + tan - 1 ( 3 ) ) As we know that, tan - 1 ( x ) + tan - 1 ( y )   = π + tan - 1 ( x + y 1 - x y )   when x y > 1 . = - π - tan - 1 ( 2 + 3 1 - 2 × 3 ) = - π - tan - 1 ( - 1 ) = - π + tan - 1 1 = - 3 π 4