Question
Question: \(\tan ^ { - 1 } \frac { c _ { 1 } x - y } { c _ { 1 } y + x } + \tan ^ { - 1 } \frac { c _ { 2 } - ...
tan−1c1y+xc1x−y+tan−11+c2c1c2−c1+
tan−11+c3c2c3−c2+…+tan−1cn1=
A
tan−1xy
B
tan−1yx
C
tan−1yx
D
tan−1(x−y)
Answer
tan−1yx
Explanation
Solution
tan−1(c1y+xc1x−y)+tan−1(1+c2c1c2−c1)+tan−1(1+c3c2c3−c2)+
= tan−1(1+yx⋅c11yx−c11)+tan−1(1+c1c21c11−c21)
=tan−1yx−tan−1c11+tan−1c11−tan−1c21+tan−1c21 −tan−1c31+…+tan−1cn−11−tan−1cn1+tan−1cn1 =tan−1(yx).