Question bank/JEE Main/Mathematics

JEE MainMathematicsEasyDefinite Integration

If tan⁡(α+β)=12 (\alpha + \beta) = \frac{1}{2}\ and tan(α=β)=13tan(\alpha = \beta) = \frac{1}{3} then tan⁡2α is 2\alpha\ is\ (where α+β\alpha + \beta and α\alpha
=
β \beta\ both are acute angles)

Show answer and solution
tan2α=tan[(α+β)+(α−β)]tan2\alpha = tan\lbrack(\alpha + \beta) + (\alpha - \beta)\rbrack
=tan⁡(α+β)+tan⁡(α−β)1−tan⁡(α−β)tan⁡(α+β)= \frac{\tan(\alpha + \beta) + \tan(\alpha - \beta)}{1 - \tan(\alpha - \beta)\tan(\alpha + \beta)}
=12+131−12  13 =1= \frac{\frac{1}{2} + \frac{1}{3}}{1 - \frac{1}{2}\ \ \frac{1}{3}\ } = 1.

Source: Grass-G / M-13 Mathematics Paper 4 Nov.docx

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