S swdbf New Member Joined Jun 30, 2009 Messages 6 Gender Male HSC 2013 Jun 30, 2009 #1 hello.. any help would be greatly appreciated. If two of the roots of the equation are equal, show that .
hello.. any help would be greatly appreciated. If two of the roots of the equation are equal, show that .
Divinity_ Member Joined Jul 12, 2009 Messages 241 Gender Female HSC 2009 Jul 13, 2009 #2 3x^2 + q = 0 x^3 + qx + r = 0 x^2 = -q/3 -qx/3 + qx + r = 2qx/3 + r = 0 x = -3r/2q -27r^3/8q^3 - 3r/2 + r = 0 -27r^3/8q^3 = r/2 -27r^3 = 4q^3r 4q^3 = -27r^2 4q^3 + 27r^2 = 0
3x^2 + q = 0 x^3 + qx + r = 0 x^2 = -q/3 -qx/3 + qx + r = 2qx/3 + r = 0 x = -3r/2q -27r^3/8q^3 - 3r/2 + r = 0 -27r^3/8q^3 = r/2 -27r^3 = 4q^3r 4q^3 = -27r^2 4q^3 + 27r^2 = 0
