So in mathematical terms this means 4 * (-0.5)^n-1 times. Since f(1) is always 4 this means you can say 4 * -0.5 (whatever your n is, minus one, and you have to multiply times 0.5 this many times.
so like f(50), that means you have to multiply f(1) * -0.5 49 times. So now you should see a pattern that whatever n equals you have to multiply f(1) n-1 times -0.5 to get the answer. to get f(4) you had to multiply f(1) * -0.5 three times. to get f(3) you had to multiply f(1) * -0.5 two times. But if you notice to get f(2) you had to multiply f(1) * -0.5 one time. then you could use f(2) to work out f(3) till you got to f(50). since you know f(1)=4 because it was given to you, you can plug in the numbers. You would have to get 47, then 46, then 45 until you got all the way back to 1.
This is why it is called 'recursive', the answer needs you to get the answer of the previous term to get your final answer.
So you would have to find f(49) So you plug it in. Well then you need to know what f(49) is. If someone were to ask you 'what is f(50).
