# include & ltstdio.h & gt
# include & ltstdlib.h & gt
# include & ltmath.h & gt
int main()
{
char op
Double num 1, num2
Printf ("Please enter a mathematical expression (such as:1+2):");
scanf("%lf %c %lf ",& ampnum 1。 Operational amplifier. num 2);
switch
{
Case "+":
Printf ("Result: %.2lf\n ",num 1+num 2);
Break;
Case'-':
Printf ("Result: %.2lf\n ",num 1-num 2);
Break;
Case' *':
Printf ("Result: %.2lf\n ",num 1 * num 2);
Break;
Case "/":
if (num2 == 0)
{
Printf ("divisor cannot be 0! \ n ");
}
other
{
Printf ("Result: %.2lf\n ",num 1/num 2);
}
Break;
Keith'':
Printf ("Result: %.2lf\n", pow(num 1, num 2)););
Break;
Case:
Printf ("Result: %.2lf\n", SIN (num1));
Break;
Case "c":
Printf ("Result: %.2lf\n", COS (num1));
Break;
Case "t":
Printf ("Result: %.2lf\n", Tan (num1));
Break;
Case "l":
Printf ("Result: %.2lf\n ",log(num 1));
Break;
Case "e":
Printf ("Result: %.2lf\n ",exp(num 1));
Break;
Default value:
Printf ("Invalid operator! \ n ");
Break;
}
Returns 0;
}