Question

Select the correct answer. If the zeros of a quadratic function are 3 and 8, what are the factors of the function? A. (x + 8) and (x − 3) B. (x − 8) and (x + 3) C. (x + 8) and (x + 3) D. (x − 8) and (x − 3)

Answer 1

C. (x-8) and (x-3)

Explanation:

When we calculate the zeros of a function, we are calculating the points where that function crosses the x axis, and to do so we have to equal the function to zero and isolate X.

`(x - 3) . (x-8) = 0`

The only way a multiplication can have a result of 0, is that any of it's factors were equal to zero. So we can take both factors and equal them to zero and isolate x to know the function's zeros.

`(x - 3) = 0\\x = 3`

`(x-8) = 0\\x = 8`