Question

prove that tan-1 1/8 + tan-1 1/5 = tan-1 1/3

Answer 1

tan-1 (1/8) = 7.12
tan-1 (1/5)= 11.31
tan-1 (-1/3) = 18.43

tan-1 (1/8) + tan-1 (1/5) = tan-1 (1/3)
7.12 + 11.31 = 18.43

Answer 2

use the caculator??????

Answer 3

^ His idea, exactly.

Answer 4

\[tan^{-1}A + tan^{-1}B = tan^{-1}{\frac{A + B}{1 -AB}}\]

Answer 5

\[tan^{-1} {\frac{\frac{1}{8} + \frac{1}{5}}{{1} - {\frac{1}{40}}}}\]

Answer 6

\[tan^{-1}{\frac{13}{39}} = tan^{-1}{\frac{1}{3}}\]

Answer 7

\[\text{^_^ That is your solution :D} \]

Answer 8

Nice job.