a2+1a2=2 then 1a+a=?
Step-1: Find 1a+a2
1a+a2=a2+1a2+2 ( As a+b2=a2+b2+2ab )
1a+a2=2+2 ( As a2+1a2=2is given)
1a+a2=4
Step-2: Find 1a+a
To find 1a+atake square root on both sides of the equation- (i) ;1a+a2=4
1a+a=2
Hence, 1a+ais 2
{1(sec2θ−cos2θ)+1(cosec2θ−sin2θ)}(sin2θcos2θ)=1−sin2θcos2θ2+sin2θcos2θ