two *x^ two *cos(two *x) - two *x*sin(two *x) = zero
2 multiply by x squared multiply by co sinus of e of (2 multiply by x) minus 2 multiply by x multiply by sinus of (2 multiply by x) equally 0
two multiply by x to the power of two multiply by co sinus of e of (two multiply by x) minus two multiply by x multiply by sinus of (two multiply by x) equally zero