Solve the quadratic:
n2-3n-28 = 0
a = 1, b = -3, c = -28
n = | -b ± √b2 - 4ac |
2a |
-b = -(-3)
-b = 3
Δ = b2 - 4ac:
Δ = -32 - 4 x 1 x -28
Δ = 9 - -112
Δ = 121 <--- Discriminant
Since Δ > 0, we expect two real roots.
√Δ = √(121)
√Δ = 11
Numerator 1 = -b + √Δ
Numerator 1 = 3 + 11
Numerator 1 = 14
Numerator 2 = -b - √Δ
Numerator 2 = 3 - 11
Numerator 2 = -8
Denominator = 2 * a
Denominator = 2 * 1
Denominator = 2
Solution 1 = | Numerator 1 |
Denominator |
Solution 1 = 7
Solution 2 = | Numerator 2 |
Denominator |
Solution 2 = -4
(Solution 1, Solution 2) = (7, -4)
(7)2 - 3(7) - 28 ? 0
(49) - 2128 ? 0
49 - 2128 ? 0
0 = 0
(-4)2 - 3(-4) - 28 ? 0
(16) + 1228 ? 0
16 + 1228 ? 0
0 = 0