If `tan^(-1) 3 +tan^(-1)x=tan^(-1)87` then x =A. `1/3`B. `1/5`C. 3D. 5

1.	If `tan^(-1) 3 +tan^(-1)x=tan^(-1)87` then x =A. `1/3`B. `1/5`C. 3D. 5
Answer» Correct Answer - B `tan^(-1)x+tan^(-1)3=tan^(-1)8 rArr tan^(-1)(3+x)/(1-3x)=pi+tan^(-1)(-1)` `=pi-tan(1)=(pi-pi/4)=(3pi)/4`.

Discussion

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