For what values of \(a\) does the equation \((a^{2}+2a)x^{2}+(3a)x+1=0\) yield no real solutions \(x\)? Express your answer in interval notation.
What have you tried?
I'd try using the quadratic formula. The bit under the square must be great or equal to zero or else the answer/s will not be real.
try subbing it in formula b^2-4ac < 0 ( this represents when a quadratic formula has no real solution)
then rearrange it
We will have no real solutions if the discriminant is < 0
So
(3a)^2 - 4(a^2 + 2a)(1) < 0
9a^2 - 4a^2 - 8a < 0
5a^2 -8a < 0 factor
a ( 5a -8) < 0
This will = 0 whenever a = 0 or a = 8/5
If a > 8 / 5....it will be positive
And if a < 0 it will be positve
So.....the values of a that produce no real solutions are when a is on the interval (0, 8/5)