IIT 1996

For all values of x and y,

sec²t =4xy(x+y)²
will be true if and only if

a) x+y\neq 0

b) x=y , x\neq0

c) x=y

d) x\neq0, y\neq0

Ans b

2 Answers

its also given x \neq0 in the answer.......why?

x=y
If x=0 ,x=y=0.Thenx+y=0.But sec tâ‰ 0

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