Question

Given the function k(x)

k(5)= =
Calculate the following values:
1
Enter an integer or decimal number [more..]
k(-4)=
k(8) =
=
=
=
k(-5) =
=
k(- 9) =
k(-8)=
2x - 5
x < -5
-5x² + 9x + 8 -5 < x < 5
-x-4
x ≥ 5
10000

Answer 1

• k(5) = -9
• k(-4) = -108
• k(8) = -12
• k(-5) = -15
• k(-9) = -23
• k(-8) = -21

Explanation:

You have a piecewise-defined function that you want to evaluate at 6 different points.

Evaluation

The first step in evaluation is to determine the applicable function definition. You do this by comparing the argument value to the list of domains.

Here, the 1st and 3rd arguments (5, 8) are in the last domain listed (x ≥ 5).

The 2nd argument (-4) is in the second domain listed (-5 < x < 5).

The last 3 arguments (-5, -9, -8) are in the first domain listed (x ≤ -5).

The corresponding function definitions are used for evaluation: put the argument value where x is, and do the arithmetic.

A calculator or spreadsheet can help. Conditional evaluation lets you implement the function definition with little trouble.