Trigonometric Identity: tan(x +/- y): Proof

in Threespeak3 months ago (edited)

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In this video I go over a quick proof of the trigonometric identities tan(x + y) and tan(x – y). The identity is simple to derive because we can use the identities which I derived in my earlier videos for sin(x +/- y) and cos(x +/- y), as well as the fact that the tangent function, tan, is just equal to the ratio of sine over cosine. Although deriving the set of identities for tan(x +/- y) is pretty simple, I show how even that process can be simplified further by utilizing the use of the notations “+/-“ and “-/+”. This allows for the solving of two identities or sets of identities at the same time! I will be utilizing this set of trig identities in my later videos so make sure to watch this video!

Download the notes in my video:!As32ynv0LoaIhvhE4tV3srF3zrHhxg

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Related Videos:

Trigonometry Identities: cos(x +/- y) = cos(x)cos(y) -/+ sin(x)sin(y) :
Trigonometry Identities: sin(x +/- y) = sin(x)cos(y) +/- cos(x)sin(y):
Trigonometry: Sine, Cosine and Tan Functions: .


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Wow... this calculation made me to remember my secondary school age and how i do calculate this mathematics back then.
Thanks for such an educative video.