use the quotient property of square roots to derive the quad
use the quotient property of square roots to derive the quadratic formula by solving the quadratic equation ax2 + bx+c=0. Hint : begin by completing the square. I need the answer step by step
Solution
ax2 + bx+c=0
Divide the equation by a:
x^2 +(b/a)x +c/a =0
add the term we just found, b2/(4a2), to both sides of the equation:
x^2 +(b/a)x +c/a +b^2/4a^2 = b^2/4a^2
This will give us our perfect square trinomial on the left
(x +b/2a)^2 = b^2/4a^2 - c/a
= (b^2 - 4a*c)/4a^2
Taking square root of both sides:
x+ b/2a = +/- sqrt(b^2 -4ac)/2a
( we put a plus or minus sign in front of the square root to account for both possibilities)
subtract b/a from both sides:
x + b/a -b/a = -b/a +/- sqrt(b^2 -4ac)/2a
x = -b/2a + /- sqrt(b^2 -4ac)/2a
x = { -b + / sqrt( b^2 - 4ac) }/2a

