Question
If \alpha and \beta are acute angles such that \tan \alpha =2, \tan \beta =3, verify \alpha +\beta =\dfrac{3\pi}{4}
If \alpha and \beta are acute angles such that \tan \alpha =2, \tan \beta =3, verify \alpha +\beta =\dfrac{3\pi}{4}
Apply sum identity for tangent function,
\tan(\alpha+\beta) = \dfrac{\tan \alpha + \tan \beta }{1-\tan \alpha\tan \beta}
= \dfrac{2+3}{1-2\times 3 } = -1
Since \alpha and \beta are acute angles
0< \alpha+\beta < \pi
Therefore,
\alpha +\beta =\dfrac{3\pi}{4}