Solve using the quadratic formula 2x2 - 2x = 1.
Solution:
Given quadratic equation : 2x2 - 2x = 1
⇒2x2 - 2x - 1 = 0
If the quadratic equation is of the form ax2 + bx + c = 0 then roots(zeros) of the quadratic equation are given by x = [-b ± √(b2 - 4ac)] / 2a
Here, b2 - 4ac = Δ where Δis called discriminant that determines the nature of roots of the given quadratic equation.
(i) If Δ > 0, then roots are real and distinct
(ii) If Δ= 0, then roots are real and repeated
(iii) If Δ < 0, then roots are imaginary or complex.
Compare 2x2 - 2x - 1 = 0 with ax2 + bx + c = 0
∴ a = 2, b = -2 and c = -1
∴ The roots are x = [-b ± √(b2 - 4ac)] / 2a = [-(-2) ± √((-2)2 - 4(2)(-1))] / 2(2)
x = [2 ± √12] / 4
x = [2 ± 2√3] / 4
x = [1 ± √3] / 2
Solve using the quadratic formula 2x2 - 2x = 1.
Summary:
The roots of the quadratic formula 2x2 - 2x = 1 are x = [1 ± √3]/ 2.
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