$${\sec ^2}\theta = {{4xy} \over {{{\left( {x + y} \right)}^2}}}\,$$ is true if and only if
A
$$x + y \ne 0\,$$
B
$$x = y,\,x \ne 0$$
C
$$x = y\,$$
D
$$x \ne 0,\,y \ne 0$$
4
IIT-JEE 1995
MCQ (Single Correct Answer)
The minimum value of the expression $$\sin \,\alpha + \sin \,\beta \, + \sin \,\gamma ,\,$$ where $$\alpha ,\,\beta ,\,\gamma $$ are real numbers satisfying $$\alpha + \beta + \gamma = \pi $$ is
A
positive
B
zero
C
negative
D
-3
Questions Asked from Trigonometric Functions & Equations
On those following papers in MCQ (Single Correct Answer)
Number in Brackets after Paper Indicates No. of Questions
