SOLUTION: Hello im am really struggling with this question,can you please help me,im desperate and this is my last option. The question says :DETERMINE THE VALUE(S) OF K FOR WHICH -2X^3

SOLUTION: Hello im am really struggling with this question,can you please help me,im desperate and this is my last option. The question says :DETERMINE THE VALUE(S) OF K FOR WHICH -2X^3 - 3X

Question 339039: Hello im am really struggling with this question,can you please help me,im desperate and this is my last option. The question says :DETERMINE THE VALUE(S) OF K FOR WHICH -2X^3 - 3X^2 +12X +20=K HAS 3 REAL ROOTS .thank you.plz help plz
Answer by galactus(183) (Show Source): You can put this solution on YOUR website!
It would be tedious to guess and check so we will use the discriminant.
The discriminant for a cubic is considerably longer than that for a quadratic.
It is:

In order for there to be three real roots, the discriminant must be > 0.
Letting

, and
making the subs it whittles down to

It has three real roots if k is less than 27.
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