Help Maths problem

[Dukat]

Hi

I was wondering if anyone could help with a problem I've been given, sort of shared, by a mate who's on a course.

He's been looking at a few of these but this one is the first that has caused a bit of trouble. I've had a go and I'm still scratching my head about some bits - alot of this is way over what I've ever been taught so its a bit 'uhm.. I think this is right..'

If anyone could help with this, and explain how its done, it would be really, really great

Any help greatly appreciated on this one guys, thanks!

 

[Dukat]

Noticed an error in how this has been written down, its supposed to be:

 

[Tuthmes]

Way over my head :<

 

[MYstIC G]

http://www.wolframalpha.com/input/?i=cos²x-sin²x+=+1-2sin²x

True

 

[DaGaffer]

Imageshack blocked by work. Although bizarrely, Flickr and Picassa aren't.

 

[Dukat]

Imageshack blocked by work. Although bizarrely, Flickr and Picassa aren't.

not used picassa much, so hope this works:

Picasa Web Albums - Pikey Reaxion - Untitled Album

 

[Bugz]

What part is he having trouble with?

 

[Scouse]

cos²x-sin²x = 1-2sin²x - Wolfram|Alpha

True

Lol

 

[Bugz]

Makes me glad I gave up trigonometry.

From what I can see: it's best to start on the left hand side. You should be able to simplify it down & just deal with the awkwardness of cleaning it all up to match the RHS

P.S other cleverer people on here can help you with this I'm sure. Infragann (sp?) is an ideal guy to send a PM to.

 

[Trem]

The answer to the problem is bacon.


Normal bacon though not any other type, just normal, salty bacon.

 

[throdgrain]

I thought that was bloody obvious Trem.

PIKEY YOU SPACKER!!!

 

[lecter]

Jim has fixed it sort of

This is the kind of direction that you should be thinking in. I cant be assed to work it out properly etc.

Its a variation on euler e^ix = cosx + isinx etc...

Also remember you add indices

 

[SheepCow]

If you ignore the question you can answer this really easily with the trigonometric identities

 

[Cadelin]

cos2x - sin2x = 1 - 2sin2x
This can be re-written as:
cos2x + sin2x - 2sin2x = 1 - 2sin2x
So you need to show that:
cos2x + sin2x = 1
There are lots of ways to show this but if you need to do it with the equations shown you can do this:
Think of e^{ix} = A
therefore e^{-ix} = 1/A
So we have:
0.25[ (A + 1/A)^2 - (A - 1/A)^2 ] = 1
0.25[ A^2 + 2 + 1/A^2 - A^2 + 2 - 1/A^2] = 1
0.25[ 2 + 2 ] = 1

 

[Deebs]

What they all said.

 

[Raven]

42















































































.

 

[Raven]

Silly minimum letters is silly.

 

[old.user4556]

Is this the equation to show that the airplane will not take off?