(2) = 1 ==> a%2A2%5Er+=+1 <-------Equation A while f(32) = 4 ==> a%2A32%5Er+=+4. <------Equation B.
Divide Equation B by corresponding sides of equation A: ==> 16%5Er+=+4 ==> r = 1/2. BTW, a+=+1%2Fsqrt%282%29, and the function is f%28x%29+=+sqrt%28x%2F2%29