Prove that `2(tan^(-1)1/4+tan^(-1)2/9)=tan^(-1)4/3`.

Explanation

To prove that \( 2\left(\tan^{-1}\frac{1}{4} + \tan^{-1}\frac{2}{9}\right) = \tan^{-1}\frac{4}{3} \), we will follow these steps:

### Step 1: Let \( x = \tan^{-1}\frac{1}{4} \) and \( y = \tan^{-1}\frac{2}{9} \)

This means we need to evaluate \( 2(x + y) \).

### Step 2: Use the formula for the sum of inverse tangents

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