[AWR83]

for which of the following functions is f(x)=f(x-1)?
a) f(x)=x^2(1-x)^2
b) f(x)=1-x
c) f(x)=1-x^2

Thanks,

[v1033]

why don't you try putting some specific examples into the functions?

e.g.

a) f(2) = 4 x 1 = 4
f(2-1) = 1 x 0 = 0
so a doesn't satisfy f(x)=f(x-1)

[v1033]

Or do I misunderstand the question?

[EuRa]

You simply substitute the equations:

For example, in B we have f(x)=1-x, substituted gives you 1-(x-1), which = 1-x+1 = 2-x. So this isn't the answer.

-----

This question is actually a very popular question to give, but it's always f(x) = f(1-x), and the answer would be A. Are you sure you wrote it the right way? Because I did all A, B, and C, and none of them worked. Are there more choices? Did you write it correctly?

[v1033]

Eura,I don't see why the reddie my answer is not wrong merely incomplete and I thought we were meant to give pointers not answers.

Awr83, I agree with eura's last point I also think none of them work and you may have posted an incorrect or incomplete question...

[EuRa]

eura,i don't see why the reddie my answer is not wrong mearly incomplete

Even if it is incomplete, it's going in the wrong direction. I don't mean to be a negative nancy, but I am a High School Math Teacher and I taught this lesson not even 3 weeks ago.

[v1033]

Then you may know of john mason's research that when stuck on a maths problem; specialising can help you on the way to generalising, which was the direction I was going in...

[EuRa]

I was in a bad mood when I wrote all this earlier. Your way (using examples) will work just fine.

I'll give you 2 positives to counter the negative comment.