Solve the quadratic:
x2+x-30
a = 1, b = 1, c = -30
x = | -b ± √b2 - 4ac |
2a |
-b = -(1)
-b = -1
Δ = b2 - 4ac:
Δ = 12 - 4 x 1 x -30
Δ = 1 - -120
Δ = 121 <--- Discriminant
Since Δ > 0, we expect two real roots.
√Δ = √(121)
√Δ = 11
Numerator 1 = -b + √Δ
Numerator 1 = -1 + 11
Numerator 1 = 10
Numerator 2 = -b - √Δ
Numerator 2 = -1 - 11
Numerator 2 = -12
Denominator = 2 * a
Denominator = 2 * 1
Denominator = 2
Solution 1 = | Numerator 1 |
Denominator |
Solution 1 = 5
Solution 2 = | Numerator 2 |
Denominator |
Solution 2 = -6
(Solution 1, Solution 2) = (5, -6)
(5)2 + 1(5) - 30 ? 0
(25) + 530 ? 0
25 + 530 ? 0
0 = 0
(-6)2 + 1(-6) - 30 ? 0
(36) - 630 ? 0
36 - 630 ? 0
0 = 0