Question
Question: If xy + yz + zx =1, than tan<sup>–1</sup> x + tan<sup>–1</sup> y + tan<sup>–1</sup> z is equal to –...
If xy + yz + zx =1, than tan–1 x + tan–1 y + tan–1 z is equal to –
A
p
B
p/2
C
0
D
None of these
Answer
None of these
Explanation
Solution
tan–1x + tan–1y + tan–1z
= tan–1 (1−xy−yz−zxx+y+z−xyz) = 2π
but will not lie in the domain of tan–1 x. so, none of these is appropriate answer.