If P=∫03π fcos2xdx and Q=∫0π fcos2xdx then
P−Q=0
P−2Q=0
P−3Q=0
P−5Q=0
Given, P=∫03π fcos2xdx …..(i)
and Q=∫0π fcos2xdx …….(ii)
From Eq.(i),
P=3∫0π fcos2xdx⇒P=3Q⇒P−3Q=0