EEE1008 2012/13 - Assignment 3 (simple plot).

A particular circuit with inductance L, capacitance C, and resistance R has a damped natural frequency given by:
         f(L,R,C) = SQRT(1/(LC - R*R/4*C*C))
where SQRT is the square root function from the <math.h> library. It is desired to study the variation of this
frequency with C.

Write a program to do the following: 

- calculate the frequency for different values of C starting from 0.01 to 0.1 in steps of 0.01;
- plot the obtained values.

The program should ask the user to enter the values of L and R. Please note that these values have to be chosen in
such a way that the term (LC - R*R/4*C*C) stays positive, otherwise the square root will not be valid. You should check
for this possibility, and terminate the program if it occurs. 

As an example, for R : 0.0001 and L : 0.1, the output might look like this:


   f      C   --------10--------20--------30--------40--------50
 32.03   0.01|                               o
 22.40   0.02|                     o
 18.27   0.03|                 o
 15.81   0.04|               o
 14.14   0.05|             o
 12.91   0.06|            o
 11.95   0.07|           o
 11.18   0.08|          o
 10.54   0.09|          o
 10.00   0.10|         o

You can use these numbers to test your program.

In order to round a floating point number f to an integer i, use the following:
   i = floor(f + 0.5);
The 'floor' function is also in the <math.h> standard C library.

Remember to compile the program with the -lm flag