Another question here.
If
show that the roots of the equation
are
Just let a, b, and c be the roots of the equation
therefore a+b+c=-b/a
ab+ac+bc=c/a
abc=-d/a
then resubstitute for x, doesn't require much complex knowledge at all if you attack it like that.
Complex number way: x=cos^2x, Let 4@= 32x^3-48^2+18x-1 which is real (cos@)
4@=pi/2+kpi= (pi+2kpi)/2= (2k+1)pi/2 where k=0,1,2,3
Agree with Tommy though, you gotta make effort yourself first, if you post up a method that you tried with your Q it shows you tried. Glad to assist though