Solving for trigonometric values Find $a+2b$ if $\tan a = 1/7$ and $\sin b=\frac{1}{\sqrt{10}}$. I had tried to solve it by trigonometric ratios but i could not. Please solve it by a method of class10 standards.

Hint:
$\tan a = \frac{1}{7}$
$\tan b = \frac{1}{3}$
$\tan(a+2b) = \frac{\tan a + \tan 2b}{1-\tan a \tan 2b}$
$\tan 2b = \frac{2tanb}{1-tan^2 b}$
You get $\tan 2b = \frac{6}{8}$
$\tan (a + 2b) = 1$
$a+2b = \arctan{1} = \frac{\pi}{4}$
