Question

Which function is a quadratic function? A. c(x) = 6x + 3x3 B. d(x) = x – 8x4 C. p(x) = –5x – x2 D. k(x) = 2x2 + 9x4

Answer 1

Answer: C.  p(x) = -5x-x^2

This is the same as p(x) = -x^2-5x

The degree is the largest exponent to determine what kind of polynomial we're dealing with.

For choice C, the degree is 2, so we have a quadratic here.

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Extra info:

• Choice A is cubic because the largest exponent is 3 (degree = 3)
• Choice B is a quartic of degree 4
• Choice D is the same story as choice B