1 . sec-1x = cosec-1y 

• A. $x^2+y^2=1$
• B. $\frac{1}{x^2}+\frac{1}{y^2}=1$
• C. $\frac{1}{x}+\frac{1}{y}=\frac{\mathrm{\pi }}{2}$
• D. $x+y=\frac{\mathrm{\pi }}{2}$

Answer: Option B

Explanation: