Answer:
See Explanation
Step-by-step explanation:
[tex]A+B= 45 \degree \\ \\ assuming \: \tan \: on \: both \: sides \\ \\\implies \: \tan( A+B)= \tan 45 \degree \\ \\ \implies \: \tan( A+B)= 1 \: \: \\ ( \because \: \tan 45 \degree = 1) \\ \\ \implies \: \frac{\tan \: A +\tan \: B }{1 - \tan \: A .\tan \: B } = 1 \\ \\ \implies \: \tan \: A +\tan \: B = 1 - \tan \: A .\tan \: B \\ \\ \purple{ \implies }\: \orange{ \bold{\tan \: A +\tan \: B + \tan \: A .\tan \: B= 1 }} \\ \\ thus \: proved[/tex]
