Consider the following recursive Java function f that takes two long arguments and returns a

float value :
public static float f(long m, long n)
{
float result =(float )m/(float )n;
if (m<0||n<0)
return 0.0f ;
else
result +=f(m∗2,n∗3);
return result;
}

Which of the following integers best approximates the value of f(2,3)?

1. A0
2. B1
3. C2
4. D3

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: C. 2

Explanation

f(2, 3) = 2/3 + 4/9 + 8/27 + … = (2/3)/(1 − 2/3) = 2. Recursion stops when m or n overflows to a negative value, by which point the remaining terms are negligible.