# Thread: Find n in the expression below.

1. ## Find n in the expression below.

Ok, I got this expression:

$(\frac{1}{\sqrt2} + 3)^n$
Then I have:
$T_4 = 3\times\sqrt2\times T_3$

Find n.

I got absolutely no idea what $T_3$ and $T_4$ are, so I have no clue how to solve this.

2. ## Re: Find n in the expression below.

Originally Posted by Legjendat
Ok, I got this expression:

$(\frac{1}{\sqrt2} + 3)^n$
Then I have:
$T_4 = 3\times\sqrt2\times T_3$

Find n.

I got absolutely no idea what $T_3$ and $T_4$ are, so I have no clue how to solve this.
Neither do I. What is n supposed to be? What is T supposed to be? What is the actual problem? What context is this in? Even a chapter reference would be good.

-Dan

3. ## Re: Find n in the expression below.

It should be obvious that you can't just put random numbers into an equation and expect that you will always get then same solution. Look back through the problem or area before the problem for references to $T_3$ and $T_4$.

4. ## Re: Find n in the expression below.

Originally Posted by topsquark
Neither do I. What is n supposed to be? What is T supposed to be? What is the actual problem? What context is this in? Even a chapter reference would be good.

-Dan
I swear this is all there was in the question in my exam, and I have never done anything like this before in class, which left me amused.

5. ## Re: Find n in the expression below.

Originally Posted by Legjendat
I swear this is all there was in the question in my exam, and I have never done anything like this before in class, which left me amused.
Well, what course this comes from? Are these Tchebyshev polynomial related questions?

A suggestion, try using binomial expansion