Define a function f from Z to N by fn 2n if n 0 but fn 1

Define a function f from Z to N by f(n) = 2n if n > 0 but f(n) = 1 – 2n if n 0. What is the value of f(–2)?

Solution

Here it is given f(n) = 2n if n > 0 but f(n) = 1 – 2n if n 0.

Now f(-2), means n 0.

So f(-2)=1-2(-2)=1+4=5. So answer is b 5