\[\frac{d}{dx}\sqrt{{{\sec }^{2}}x+\text{cose}{{\text{c}}^{2}}x}=\][DSSE 1981]

\[-4\cos \text{ec 2}x.\cot 2x\]

\[\frac{d}{dx}\sqrt{{{\sec }^{2}}x+\text{cose}{{\text{c}}^{2}}x}=\][DS

1.	\[\frac{d}{dx}\sqrt{{{\sec }^{2}}x+\text{cose}{{\text{c}}^{2}}x}=\][DSSE 1981]
A.	\[4\cos \text{ec 2}x.\cot 2x\]
B.	\[-4\cos \text{ec 2}x.\cot 2x\]
C.	\[-4\cos \text{ec }x.\cot 2x\]
D.	None of these
Answer» C. \[-4\cos \text{ec }x.\cot 2x\]