SOLUTION: Hi,
I'm currently studying solving quadratic inequalities, and I'm having a bit of trouble.
I'm trying to solve 1/2x^2 + 3x (less than or equal to) -6. Since I couldn't facto
Question 28934: Hi,
I'm currently studying solving quadratic inequalities, and I'm having a bit of trouble.
I'm trying to solve 1/2x^2 + 3x (less than or equal to) -6. Since I couldn't factor the equation, I tried using the quadratic formula, however I got a complex number. I'm not exactly sure how to test the complex numbers, so I'm a bit lost on how to solving this.
Thanks for any help you can provide! Answer by Fermat(136) (Show Source):
You can put this solution on YOUR website! There's a mistake in this question.
As you found out, you will end up with complex roots.
That's the problem!
You can't compare complex numbers. Unless they are both totally real or totally imaginary.
You can't have an inequality such as 3 < 2i, or even 2 + 5i > 1 - 3i.
You can test this out by graphing the curve of (1/2)x² + 3x and see where its lowest point is wrt the line y = -6.
As you can see, the line y = -6 is less than the curve (1/2)x² + 3x at all times, so that inequality never holds.
