Use [ code] and [ /code] (without the leading spaces) for your code.

Code (Text):

#include <iostream>
using namespace std;
int main()
{
int deg;
cout << "Enter the degree of the polynomial:" << endl;
cin >> deg ;
cout << "For the polynomial f(x)=";
if (deg ==3)
{
cout<<"For the polynomial f(x)=C1*x^3+C2*x^2+C3*x^1+C4, enter C1, C2, C3, C4 in order:";
}
else if(deg==2)
{
cout<<"For the polynomial f(x)=C1*x^2+C2*x^1+C3, enter C1, C2, C3 in order:";
}
else if (deg==1)
{
cout<<"For the polynomial f(x)=C1*x+C2, enter C1, C2 in order:";
}

return 0;

As phyzguy points out, you're missing the final brace at the end of main.

There is another error as well - you are missing an else clause at the end of your if ... else if clauses.

Also, you apparently want the program user to enter the coefficients of the various powers of x, but you don't have input statements to do this, and you don't have variables declared to hold c1, c2, etc.