Question

Find all values of A that generate imaginary roots:
0=ax^2+3x-9

Answer 1

b^2 - 4ac must be negative. So, find a such that this value is negative (<0).

Answer 2

I tried but had trouble doing that...

Answer 3

b = 3
c = -9
a = a

b^2 - 4ac = 9 + 36a < 0
=> 36a < -9
=> a < -1/4

Answer 4

Thanks!!!