Q.

Assertion(A): csc 245°-cot 245°=1

Reason(R): csc 2θ-cot 2θ=1 for all values of θ.

1 Both A and R are true, and R is the correct explanation of A  
2 Both A and R are true, but R is not the correct explanation of A.  
3 A is true, but R is false  
4 A is false, but R is true  

Ans.

(3)

Assertion (A) is true, but Reason (R) is false as the identity csc 2θ-cot 2θ=1 is not defined for θ = 0°.