write the following functions in a C program not C++.

1. complex complex_add(complex, complex);

complex_add() will add the corresponding fields of two complex variables together and will return a complex value that represents the sum. For instance, if complex_add() is invoked with the values (1.0, 2.0) and (3.0, 4.0), it will return the value (4.0, 6.0). complex complex_neg(complex);

2. complex_ neg() will return the negative form of the argument. E.g., -1.0 times the value of each field.

complex complex_sub(complex, complex);

3. complex_ sub() is similar to complex_add() except that it subtracts the second argument from the first. You should implement this function with something like: complex_add(arg1, complex_neg(arg2))