Staring with the equation $y=x^2-4$ determine the zeros of the equation using the quadratic formula.

Code $1$: Write a code to put $a,b,$ and $c$ into a file

Code $2$: read the file and perform the calculation $x=\frac{-b\sqrt[\phantom{2}]{b^2-4ac}}{2b}.$

Write in C and show code please