Pretty easy I think but I was out sick when they did it in school and none of the trigonometric examples in my book cover this:
How does sin 2 a = 2sinacosa
Maths help???
Pretty easy I think but I was out sick when they did it in school and none of the trigonometric examples in my book cover this:
How does sin 2 a = 2sinacosa
Well, I open my eyes and I see things. I've seen spirits moving through the walls. I've seen a vortex coming through the wall. I've seen amorphous little balls of light bouncing all around in the front yard through the window. I've seen giant bugs on the floor. I was in a hotel room in Amarillo, Texas, and all I remember is standing on the bed and seeing the whole wall in front of me filled with lights that were [makes popping sound] popping like popcorn out of the wall. Then I'll wake up and I go "Wow, I was standing on my bed and staring at this wall."
what do you mean. what values of a satisfy(all of them) or a proof of the identity (use sin(x+y) = sinxcox + sinycosy)
maybe
2sin(a)cos(a)
2(1/2(sin(a+a)+sin(a-a))): product to sum formula
sin(2a)+sin(0)
sin(2a)+0
sin(2a)
thats the closest I can get
Its a double angle identity. This is my only idea of how to prove it involves a sum to product function but I keep on running into dead ends.
sin(x+x) = sinxcox + sinxcox = 2sinxcosx = sin(2x)
also i mistyped the identity in my first post its sinxcosy + cosxsiny
It's a proof of identity question.
That looks right but it also looks way too simple to be the answer. Is there a way we can throw the sin rule/cosine rule/angle formula in the middle to prove of or something?Originally Posted by God
so lord, do I just not exist or something
Why do you want it to be complex, Lord? It has a very simple answer, that is the elegance of Math.
Originally made by LM:
~ I have said nothing because there is nothing I can say that would describe how I feel as perfectly as you deserve it. -- Kyle Schmidt ~
~Silence is one of the hardest arguments to refute. -- Josh Billings ~
* dragon_berry**Fallen_Wings*
Everytime I see this thread I read it as Meths help
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