## gerryliyana Group Title Help one year ago one year ago

1. lillybeth123 Group Title

huh?

2. abb0t Group Title

Is this a medical emergency? If so, please call your local emergency number.

3. gerryliyana Group Title

it's math emergency

4. lillybeth123 Group Title

wats ur question?

5. gerryliyana Group Title

These are the pictures that I've uploaded for my question

6. lillybeth123 Group Title

oh glob, sorry i cant help, thats too hard, bye. :)

7. abb0t Group Title

I vaguely remember doing this, but I think you want to use the exponential form of cosh and sinh to prove it.

8. cblrtopas Group Title

Yeah, noob google series expansion of hyperbolic cosine and sine

9. cblrtopas Group Title

So sin z is equal to some summation. You multiply it by i. Work out a few terms in the summation making sure to remember that i^2=-1 and try to simplify it to look like the sinh z formula.

10. gerryliyana Group Title

For -1 < p < 1 prove that $\sum_{n=0 }^{\infty} p^{n}\cos nx =\frac{ 1= pcos x }{ 1-2pcosx + p^2 }$