L.H.S: sec^2x+ cosec^2x
=(1+tan^2x)+(1+cot^2x)
=2+tan^2x+cot^2x
= 2+ sin^2x / cos^2x +cos^2x/sin^2x
= 2+(sin^4x+cos^4x)/sin^2x cos^2x
=2+ [(cos^2x-sin^2x)2+2sin^2x cos^2x]/sin^2x cis^2x
=2+(cos^2 2x)/sin^2x cos^2x +2
= 4+cos^2 2x/sin^2x cos^2x
Because max.value of sinx and cosx is 1.
Therefore, 4+cos^2 2x/sin^2x cos^2x>4
