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### A.3. Chapter 3

#### A.3.1. Exercise 1 solution

Use the proper man page requests that appear in the following table. Note that printf overlaps with a command-line function, so you must specifically request the section for C functions. The section is optional for the other man pages.

FunctionMan Page
printf"3 printf"
scanf"scanf" or "3 scanf"
pow"pow" or "3 pow"

#### A.3.2. Exercise 2 solution

1. Change the instances of int in Calculate.h to double. This includes

`double calculate(const double a, const double b, const char op);`
2. Change the instances of int in Calculate.c to double. This includes:

```double calculate(const double a, const double b, const char op)
{
double result;```
3. Replace the main function in main.c with the following code:

```int main (int argc, const char * argv[])
{
int count;
char op;

// print the prompt
printf("Enter an expression: ");

// get the expression
count = scanf("%lg %c %lg", &a, &op, &b);
if (count != 3) {
exit(1);
}

// perform the computation

printf("%lg %c %lg = %lg\n", a, op, b, answer);

return 0;
}```

#### A.3.3. Exercise 3 solution

1. Add the following include after the other includes in Calculate.c:

`#include <math.h>`
2. Add the following case entries to the switch statement. Here is the final switch statement:

```case '/':
result = a / b;
break;
case '\\':
result = (int)a / (int)b;
break;
case '%':
result = (int)a % (int)b;
break;
case '^':
result = pow(a, b);
break;```