mathcalculus
posted by Shreya on .
solve equation x^22x6 using quadratic formula. i not get how to do this and it says quadratic formula.

you cannot solve it since you cant square root a negative number... unless 2x was positive 2x.

sorry i missing part of question whole question be x^22x6 = 4. and answer have to be 1+sqrt3, 1+sqrt11 i just not get how to get this.

f(x) = x^2  2x  6 has roots 1±√7 = 1.65,3.65
Between the roots, f(x) < 0 and we have
(x^22x6) = 4
x^2  2x  2 = 0
x = 1±√3
both those values are in the interval, so they're ok as solutions
Outside that interval,
x^22x6 = 4
x^2  2x  10 = 0
x = 1±√11
both those values are outside the interval, so they're ok as solutions