sin and cosine work, please help?

Question

anonymous · Answer

$$\sin^2 \alpha+ \cos^2 \alpha =$$

anonymous · Answer

Should equal 1

imstuck · Answer

This is an identity that is pretty popular.  Do you know it?

anonymous · Answer

identities arent my best, but im here or there on info about them.

anonymous · Answer

How does it equal one? or do you know where i can find a good identity chart or set of rules?

anonymous · Answer

It equals one simply because of the rule that's given, and as it is an important rule, you'll want to know it. We know it's true because we are told so.

anonymous · Answer

You should check out some Unit Circles to understand why it equals to one

xapproachesinfinity · Answer

no there is a reason why it is 1
it is the Pythagorean thm using trig function in the unit circle

anonymous · Answer

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anonymous · Answer

example
^^^^^

xapproachesinfinity · Answer

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anonymous · Answer

Ah... thanks pal,

xapproachesinfinity · Answer

okay now from that triangle we have
x^2+y^2=r^2 but r is just 1
so x^2+y^2=1, yes?

xapproachesinfinity · Answer

welcome bro^_^

xapproachesinfinity · Answer

that equation is know as circle equation in the unit circle

anonymous · Answer

Haha um, thank you all for the help of understanding this, a bit more. I understand that this identity  equals 1 and i have to get the rest of the rules down, thank you all for the help.

xapproachesinfinity · Answer

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