**Evaluating Math Functions**

In this example, you’ll use nested *if* conditions to solve a math problem. You’ll write a program that evaluates *y*=*f*(*x*), for a given input, *x*:

The complete program’s in Listing 7-11, along with the output from four sample runs.

** **

**Code**

** **

' Calculated y as a function of x

TextWindow.Write("Enter x: ")

x = TextWindow.ReadNumber()

y = 0

**If** (x > 0) **Then**

**If** (x <= 10) **Then** *' 0 < x <= 10*

y = x

**Else** *' x > 10*

**If** (x <= 20) **Then** *' 10 < x <= 20*

y = 20 - x

**EndIf**

**EndIf**

**EndIf**

TextWindow.WriteLine("y(" + x + ") = " + y)

**Output**:

Enter x: -5

y(-5) = 0

Enter x: 5

y(5) = 5

Enter x: 15

y(15) = 5

Enter x: 25

y(25) = 0

The comments in the program will help you understand each step.

Trace through the program using a few different values for x. (Plug a number in for x and then work through each step on pencil and paper. Then enter the number as a user of your program to check your answer.)

Have a Small and Basic week!

- Ninja Ed & Majed Marji

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