Is sqrt mean square root?:p
If so then ,by dividing with RHS ,the equation go to:
(x^2-5)lcos(x)l = lxlcosx/2
square--> [cos(x)]^2*(x^2-5)^2=x^2*[cosx]^2*1/4
---> cos x =0 is solution ie x=+-(pi/2) or 3pi/2 is solution(between -2 and 6)
then divide for cosx^2 the equation is:
x^4 -...