What is the value of mystery(4)?
public static int mystery(int n)
{
if(n == 1) return 1;
else return 3*mystery(n-1);
}
What is the value of strange(4)?
public static int strange(int n)
{
if(n == 0) return 2;
else return strange(n-1) + 3;
}
Write a Java definition of public static method abs(x), taking a value x of type double and producing its absolute value.
Write a Java definition of public static method fourthroot(x), taking a value x of type double and producing its fourth root value. You can use function sqrt(x), which computes the square root of x. The fourth root of x is the square root of the square root of x.
Using recursion, and not a loop, write a Java definition of public static method sum(n) = 1 + 2 + ... + n. (Hint. Notice that sum(1) = 1. Also notice that, for n > 1, sum(n) = sum(n-1) + n.)
Using recursion and not a loop, write a public static method anySevens(n) in Java that takes an integer parameter n and returns 1 if there are any 7's in the decimal representation of n, and 0 otherwise. For example, anySevens(974) = 1, anySevens(7) = 1 and anySevens(32) = 0. Function anySevens should require its parameter n to be nonnegative. For this problem, do not use any form of loop, and do not alter the value of any variable that already has a meaningful value.
Hint. You can get the rightmost digit of n by computing n % 10. You can get all but the rightmost digit by computing n/10. For example, if n is 1974 then n % 10 is 4 and n/10 is 197. Notice the following facts.