Can anyone teach me how to do this question ?
24. A root of the quadratic equation ax^2-x+6=0 is 3/2.
(a) Find the value of a.
(b) Hence find the other root of the equation by using the quadratic formula.
F.4 Mathematics Quadratic Equations
2007-10-20 8:46 am
回答 (1)
2007-10-20 9:19 am
✔ 最佳答案
a) Sub x = 3/2 into the equationa(3/2)^2 - 3/2 + 6 = 0
9/4 a - 3/2 + 6 = 0
a = -2
b) Sub a = -2 into quadratic formula
x = 1+- square root{ (-1)^2 - 4(-2)(6) } / 2(-2)
x = 1 +- square root (1 + 48) / -4
x = 1 +- square root 49 / -4
x = (1 +- 7) / 4
x = 8/-4 or -6/-4
x = -2 or 3/2
so, the other root is -2
Hope u understand, it is difficult to type!
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