A) \[x+y\]
B) \[x+\frac{1}{y}\]
C) \[\frac{1}{x}+\frac{1}{y}\]
D) \[x+2y\]
Correct Answer: C
Solution :
\[\cot B-\cot A=y\]\[\Rightarrow \]\[\frac{\tan A-\tan B}{\tan A.\tan B}=y\] \[\frac{x}{y}=\tan A.\tan B\] \[\therefore \]Now, \[\cot (A-B)=\frac{1}{\tan (A-B)}\] \[=\frac{1+\tan A.\tan B}{\tan A-\tan B}\] \[=\frac{1+x/y}{x}=\frac{1}{x}+\frac{1}{y}\]You need to login to perform this action.
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