What have you tried? The policy of this forum is to help students with their problems, not simply solve it for them.This is the question I am struggling with
if f(1) = 3 and f(n) = -2f(n-1) + 1 than f(5) = ???
I know the answer to the question is 43, I have no idea how it is 43, if someone can explain this to me it would be greatly appreciated.
What have you tried? The policy of this forum is to help students with their problems, not simply solve it for them.
As a hint, what do you need to know to find f of any number? Look at the formula for the answer.
OK, can you find f(2)?My issue is that I have literally no idea what to do, I know the answer is 43 because it is off of a regent review packet, but there is no explanation given. I figure that the n in the (n-1) is 5 but I have no idea what -2f even means so everything I have tried has been mostly gibberish. Can you tell me what -2f means in this instance?
OK, can you find f(2)?
-2f(n-1) means -2 times f(n-1)My issue is that I have literally no idea what to do, I know the answer is 43 because it is off of a regent review packet, but there is no explanation given. I figure that the n in the (n-1) is 5 but I have no idea what -2f even means so everything I have tried has been mostly gibberish. Can you tell me what -2f means in this instance?
-2f(n-1) means -2 times f(n-1)
In -2 (5-1) + 1 what happened to the f?so if I do -2 tims f(n-1) + 1 and I am looking for f(5) than I would do -2 (5-1) + 1 which equals -7, the answer is -43, clearly I am missing something
In -2 (5-1) + 1 what happened to the f?
I did not say that -2f(n-1)=-2(n-1).
This is simply not true as you were told that f(n) = -2f(n-1) + 1.I have no idea what the f could be in the question.
This is simply not true as you were told that f(n) = -2f(n-1) + 1.
Come on, just plug in 2 for n and let's see what you get. You CAN do this!
Just substitute 2 for n in f(n) = -2f(n-1) + 1 and report back with what you get. If you think math you may make a mistake. Just think that instead of writing n I will write 2 and I will not change ANY other detail at all.you said to substitute the function in for f, the problem is the function already has an f in it, so I don't get how that would get me to an answer
f(5) = -2f...
instead of f I type in the function so
-2(-2f(5-1)+1)(5-1) +1, that would still leave me with a random f that I have no idea how to get rid of or solve for.
Just substitute 2 for n in f(n) = -2f(n-1) + 1 and report back with what you get. If you think math you may make a mistake. Just think that instead of writing n I will write 2 and I will not change ANY other detail at all.
Of course not! f(n) is a function just like f(x). f(x) is NOT f times x!ok so...
-2f(2-1) +1
-4f+2f + 1
f(2) =-2f +1
like that?
Of course not! f(n) is a function just like f(x). f(x) is NOT f times x!
Just write down f(n) = -2f(n-1) + 1 EXACTLY as it is except write 2 for n. Do not add. Do not subtract. Do not multiply. Just copy
Now compute 2-1 and replace 2-1 with the result.so
f(2) = -2f(2-1) +1
Now compute 2-1 and replace 2-1 with the result.
You should write the full equation. f(2)=-2f(1)+1. Do you know what f(1) equals? Hint, it was given! So what does f(2) equal?-2f(1) + 1
You should write the full equation. f(2)=-2f(1)+1. Do you know what f(1) equals? Hint, it was given! So what does f(2) equal?
You need to get a better grip on what an equal sign, = , means. It means that you can replace what is on the lhs of the equal sign with what is on the rhs of the equal sign and visa versa. So yes, replace f(1) with 3 and compute f(2).f(2) = -2f(1) + 1, I know f(1) = 3, but how would I use that information to find f(2)? Would I put a 3 in for f? Is this a sequence? I am still extremely confused, sorry for my daftness.