Question

Evaluate the function for the indicated values of x.

f(−10) =

f(2) =

f(−5) =

f(−1) =

f(8) =

Answer 1

f(-10) = -19

f(2) = 4

f(-5) = -9

f(-1) = 1

f(8) = -5

Explanation:

The domain for x is all real numbers (without restrictions). For instance, if f(x) = x^2, on -5 < x < 5, on negative x, you must use f(x) = (-1)^2 to get 1.

If x is >= 5, then the range is 3 - x, so f(x) = 3 - x, if x >= 5.

If x is <= -5, then the range is 2x + 1, so f(x) = 2x + 1, if x <= -5.

Answer 2

f(-10) = -19

f(2) = 4

f(-5) = -9

f(-1) = 1

f(8) = -5

Explanation:

This is relatively simple if you understand the concept. All you have to do is take each number and then look at each inequality to see where it fits.

For example, if you take 2 and look at the first inequality, you see that 2 is not less than or equal to 5. Now if you look at the second inequality, you see that 2 is both greater than -5 and less than 5. Since 2 fits in the second inequality, you plug it into the second equation.

These functions where you have to see where the x-value fits are called piecewise functions and you will see them a lot in higher level math.

(disclaimer: I evaluated the numbers quickly, so I would doublecheck it, but I am pretty sure I didn't mess up)