What is the axis of symmetry for f (x) = - 2x^2+20x-42

Question

Mathematics

Addison Stout

22 August, 17:59

What is the axis of symmetry for f (x) = - 2x^2+20x-42

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Danielle · Answer 1

F (x) = - 2x² + 20x - 42

This is a quadratic expression.

For a general expression ax² + bx + c, the axis of symmetry x = - b/2a

Comparing - 2x² + 20x - 42 to ax² + bx + c, a = - 2, b = 20, c = - 42

Axis of symmetry, x = - b/2a

x = - 20 / (2 * - 2) = - 20/-4 = 5

Therefore axis of symmetry is x = 5.