Determine the value(s) of k so that the quadratic relation y = x²+kx+9 has two equal real roots
Please include a simple explanation of the steps!
Thanks!
Quadratic Equation - Find the two equal real roots?
2011-06-07 1:16 am
回答 (4)
2011-06-07 1:22 am
✔ 最佳答案
The two solutions are equal when the discriminant = 0.For ax^2 + bx + c, the discriminant is b^2 - 4ac.
For your problem,
0 = k^2 - 4(1)(9)
0 = k^2 - 36
k^2 = 36
k = 6 or k = -6
2016-11-09 1:21 pm
kx^2 + (ok-3) x + a million = 0 2 equivalent actual roots skill discriminant = 0 => (ok - 3)^2 - 4(ok)(a million) = 0 => ok^2 - 6k + 9 - 4k = 0 => ok^2 - 10k + 9 = 0 (ok - 9)(ok - a million) = 0 => ok = 9 or ok = a million ***************************************... for x^2 + (ok-3) x + ok = 0 : => (ok - 3)^2 - 4k = 0 additionally ok = 9 or a million
2011-06-07 1:20 am
so you take the square root of 9 which is 3 and you know 3 has to be positive since its plus kx and 3 +3 = 6 therefore k=6 so the roots would be (x+3)(x+3)
收錄日期: 2021-04-30 01:13:08
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110606171631AAPDM4L