## anonymous 5 years ago what does sequence have to do with trig?

1. TuringTest

which sequence?

2. anonymous

the one with a big ∑

3. TuringTest

That's called a series. The symbol is called Sigma A sequence means you do not add up the terms, a series means you do. There are a number of series related to trig functions, but I am guessing you mean the Taylor series expansion of sine and cosine...$\cos x=\sum1-\frac{x^2}{2!}+\frac{x^4}{4!}-\frac{x^6}{6!}+\dots$$\sin x=\sum x-\frac{x^3}{3!}+\frac{x^5}{5!}-\frac{x^7}{7!}+\dots$right?

4. anonymous

something like that but that goes into calc very fast when i just grabbed a trig book lol the whole problem when 6 64 ∑ 2 ^-k k=1 this is what the whole thing (problem) looks like

5. TuringTest

Most functions f(x) can be written in terms of Taylor series$\sum_{n=0}^{\infty}\frac{f^{(n)}(a)}{n!}(x-a)^n$However the problem you posted$64\sum_{k=1}^{6}2^{-k}$is a very different one, and has no relation to trig functions that I personally know of.

6. anonymous

:\

7. anonymous

it will be a while before i get to taylor series i only got to limits i am back tracking on trig

8. anonymous

thank you vm

9. TuringTest

is that series that I posted second the correct one?

10. anonymous

i was just focusing on what you said not the problem itself that if was or not part of trig at the moment then i looked at the calc part so ty very much :)

11. TuringTest

welcome :)