Your program will recurse forever, consuming hypothetically infinite amounts of memory. "if(x==1.41421509)" will probably never return true, because floating point values don't have infinite precision. You should do

Code:

if(fabs(x-1.41421509) < .001)

instead, to see if it's approaching a value precise enough. Adjust ".001" to taste.

Since your computer probably won't let you have infinite amounts of stack space, recursing forever causes it to crash.

Why not use a loop instead of having calcx() call itself?

Code:

do
{
    // Calculate result
    // Set new ranges
    // Only if not precise enough, loop through again
} while(fabs(x-1.41421509) >= 0.001);

---------- Post updated at 10:53 AM ---------- Previous update was at 10:50 AM ----------

You should probably also have a count value, so if it gets stuck, it'll give up after a few thousand loops.