Question

What is the range of the function y=(x+2)(x-4)

Please explain how you got it as well

Answer 1

Lets simplify the function into it's correct quadratic form first, just by multiplying the parenthesis.

Y = x^2 -2x -8

Now we know that the range is from the minimum y-value to the maximum (if there is one)

In functions like this, they have the form y = ax^2 + bx + c, where c is the minimum or maximum for the given function

In this case, it's a minimum because there aren't any y points on the graph smaller than -8

That means the range is: y >= -8

Answer 2

The range is between -2 and +4.

Explanation:

To find range you just need to get X ignoring the Y.

(X+2) is X= -2

(X-4) is X = +4