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Trigonometry! 157

Geometry Level 4

\[\sec^{2}\theta=\frac{4xy}{(x+y)^{2}}\] is true if and only if :

This problem is part of the set Trigonometry.

\[x\neq 0,y\neq 0\] \[x= y\] \[x= y,x\neq0\] \[x+y\neq0\]

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by Omkar Kulkarni

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