Question

50 pts !!! Help please

Answer 1

Pi/4 is the answer you are looking for.

Answer 2

`INVERSE \: \: TRIGONOMETRY \\ \\ \\ Given \: \: expression \: - \\ \\ {tan}^( - 1) (1)/(3) + {tan}^( - 1) (1)/(5) + {tan}^( - 1) (1)/(7) + {tan}^( - 1) (1)/(8) \\ \\ \\ Using \: \: the \: \: identity \: \: - \\ {tan}^( - 1) x + {tan}^( - 1) y = {tan}^( - 1) (x + y)/(1 - xy) \\ \\ \\ {tan}^( - 1) (1)/(3) + {tan}^( - 1) (1)/(5) + {tan}^( - 1) (1)/(7) + {tan}^( - 1) (1)/(8) \\ \\ = {tan}^( - 1) (( (8)/(15) )/(1 - (1)/(15) ) ) + {tan}^( - 1) ( ( (15)/(56) )/(1 - (1)/(56) ) ) \\ \\ = {tan}^( - 1) (8)/(14) + {tan}^( - 1) (15)/(55) \\ \\ = {tan}^( - 1) ( ( (4)/(7) + (3)/(11) )/(1 - (4)/(7) * (3)/(11) ) ) \\ \\ = {tan}^( - 1) (65)/(65) = {tan}^( - 1) 1 \\ \\ \\ = \: \: \: (\pi)/(4) \: \: \: \: \: \: \: \: \: \: \: Ans.`