Question
Question: The equation \(\sec^{2}\theta = \frac{4xy}{(x + y)^{2}}\) is only possible when...
The equation sec2θ=(x+y)24xy is only possible when
A
x=y
B
x<y
C
x>y
D
None of these
Answer
x=y
Explanation
Solution
∵cos2θ≤1
⇒ sec2θ=(x+y)24xy≥1⇒4xy≥(x+y)2⇒(x−y)2≤0Which
is possible only when x=y (∵x,y∈R)