Definite/indefinite (1 Viewer)

[enigma_1]

How do you do b and c.

For b the answer is no values, why?

 

[QZP]

b) For a parabola ax^2 + bx + c to be a negative definite, a < 0 (concave down) and b^2 - 4ac < 0 (no zeroes). You will find there are no values for k which satisfy both conditions.
c) Indefinite means not definite. Which means there ARE zeroes, i.e. b^2 - 4ac >= 0.

 

[Drongoski]

The question has worded incorrectly.

The author should have worded: Find the values of k for which: ("3k-5)x² + 2(4-k)x + 4 is"

and not: " . . . (3k-5)x² +2(4-k)x + 4 = 0 is"

because only the quadratic function, (in this case) can be positive definite etc etc, and not the corresponding quadratic equation.