Inverse Trigonometric Functions Question 38
Question: If $ {{\tan }^{-1}}x+{{\tan }^{-1}}y=\frac{\pi }{4} $ then
[Karnataka CET 2005]
Options:
A) $ x+y-xy=1 $
B) $ x+y+xy=1 $
C) $ x+y+xy+1=0 $
D) $ x+y-xy+1=0 $
Show Answer
Answer:
Correct Answer: B
Solution:
$ {{\tan }^{-1}}x+{{\tan }^{-1}}y=\frac{\pi }{4} $ ; $ {{\tan }^{-1}}( \frac{x+y}{1-xy} )={{\tan }^{-1}}1 $
$ \frac{x+y}{1-xy}=1 $ ; $ x+y+xy=1 $ .
BETA
