For what values of x is $f (x) = - 2 x^{2} - 6 x + 4$ $f(x)=-2x^2-6x+4$ concave or convex?

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Answer 1 · 2017-04-08T02:06:46

The function is concave everywhere.

Algebra

The graph is a parabola that opens downward. So it is concave.

Calculus

$f'(x) = -4x-6$

$f''(x) = -4$

Since $f''(x)$ is negative for all $x$ , the function is concave for all $x$ .

For what values of x is f(x)=-2x^2-6x+4f(x)=−2x2−6x+4f(x)=-2x^2-6x+4 concave or convex?