Question 767408
 Find the value of k so that the equation 2x^2-kx+8=0 will have imaginary roots .
.
From part of the "quadratic equation" we have:
{{{sqrt(b^2-4ac)}}}
The equation will have imaginary root if:
(b^2-4ac) < 0
plug in given values:
((-k)^2-4(2)(8)) < 0
(k^2-64) < 0
k^2 < 64
k < sqrt(64)
.
answer: (in interval notation)
(-8, 8)
That is, -8 < k < 8