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If tan-1x + tan-1y = π/4 than write the value of x + y + xy. |
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Answer» tan-1x + tan-1y = π/4 ⇒ tan-1((x + y)/(1 - x.y)) = π/4 ⇒ (x + y)/(1 - x.y) = tan(π/4) = 1 ⇒ x + y = 1 - xy ⇒ x + y + xy = 1 |
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