Answer:
D. 1
Step-by-step explanation:
We have the expression, [tex]\frac{\csc^{2}x\sec^{2}x}{\sec^{2}x+\csc^{2}x}[/tex]
We get, eliminating the cosecant function,
[tex]\frac{\sec^{2}x}{\frac{\sec^{2}x}{\csc^{2}x}+1}[/tex]
As, sinx is reciprocal of cosecx and cosx is reciprocal of secx,
i.e. [tex]\frac{\sec^{2}x}{\frac{\sin^{2}x}{\cos^{2}x}+1}[/tex]
i.e. [tex]\frac{1}{\cos^{2}x}\times \frac{\cos^{2}x}{\sin^{2}x+\cos^{2}x}[/tex]
Since, we know that, [tex]\sin^{2}x+\cos^{2}x=1[/tex]
Thus,
[tex]\frac{1}{\cos^{2}x}\times \frac{\cos^{2}x}{\sin^{2}x+\cos^{2}x}=1[/tex]
So, after simplifying, we get that the result is 1.
Hence, option D is correct.