How do you find the axis of symmetry, and the maximum or minimum value of the function f(x)= -3x^2+7x-4f(x)=3x2+7x4?

1 Answer
Sep 22, 2017

See the explanation: A sort of cheat approach.

Explanation:

Firstly the coefficient of x^2x2 is negative so the graph is of form nnn. Thus we have a maximum.

Write the equation as: y=-3(x^2color(red)(-7/3)x)-4y=3(x273x)4

Thus x_("maximum")xmaximum is at x=(-1/2)xx(color(red)(-7/3))=+7/6x=(12)×(73)=+76

Now it is just a matter of substitution to determine y_("maximum")ymaximum

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