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Solve `tan^(-1) x + cot^(-1) (-|x|) = 2 tan^(-1) 6x` |
Answer» If `x gt0` `tan^(-1) x + cot^(-1) (-x) = 2 tan^(-1) 6x` `rArrr tan^(-1) x + pi - cot^(-1) x = 2 tan^(-1) 6x` `rArr (pi)/(2) + 2 tan^(-1) x = 2 tan^(-1) 6x` `rArr tan^(-1) 6x - tan^(-1) x = (pi)/(4)` `rArr tan^(-1).(6x - x)/(1 + 6x^(2)) = (pi)/(4)` `rArr (5x)/(1 + 6x^(2)) =1` `rArr 6x^(2) -5x + 1 = 0` `rArr x = (1)/(2), (1)/(3)` If `x lt 0` `tan^(-1) x + cot^(-1) x = 2 tan^(-1) 6x` `rArr tan^(-1) 6x = (pi)/(4)`, This is not possible as `x lt 0` |
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