Notes for Trigonometry (1 Viewer)

[od9895]

Hey guys, I really need some help for trigonometry. I started tutoring just december last year and we started trigonometry. I missed half the topic. Do you guys have any notes on proving and expanding identities, half angle formula, double angle formula and the unit circle. If so could you guys please contribute because I tried looking them up on the internet but nothing came up.

Thanks

 

[CallanT]

Shouldn't this be in the maths forum?

EDIT:
Not meaning to sound rude.

 

[RivalryofTroll]

Hey guys, I really need some help for trigonometry. I started tutoring just december last year and we started trigonometry. I missed half the topic. Do you guys have any notes on proving and expanding identities, half angle formula, double angle formula and the unit circle. If so could you guys please contribute because I tried looking them up on the internet but nothing came up.

Thanks

Yeah, can you just wait for like 1 hour or so?
Within that time, someone should be able to post it up but if not, I'll post it by then!

 

[SpiralFlex]

I could make some worked examples for you on the forum if you want. I am not sure where you are up to. Care to tell me young child?

 

[RivalryofTroll]

2U Identities
tanx = sinx/cosx
secx = 1/cosx
cotx = cosx/sinx OR 1/tanx
cosecx = 1/sinx
cos^2x + sin^2x = 1
sec^2x - tan^2x = 1

 

[SpiralFlex]

It is also good to explain where the formulae actually comes from. I shall do that via request.

 

[RivalryofTroll]

Sorry if there's any silly mistakes because I'm rushing through this!
Expansion
sin(A+B) = sinAcosB + sinBcosA
sin(A-B) = sinAcosB - sinBcosA
cos(A+B) = cosAcosB - sinAsinB
cos(A-B) = cosAcosB + sinAsinB
tan(A+B) = tanA + tanB/ 1 - tanAtanB
tan(A-B) = tan A - tanB/ 1 + tanAtanB

 

[Peeik]

If you have cambridge then i believe they have a fairly solid explanation of these identities (if not wait for spiralflex ). You could also try this website http://www.sosmath.com/trig/trig.html however i find the font quite irritating haha. Hope this helps, and if you have any questions feel free to ask us!

 

[RivalryofTroll]

Double Angle Formulae
Sin2x = 2sinxcosx
Cos2x = cos^2x - sin^2x
= 2cos^2x - 1
= 1 - 2sin^2x
tan2x = 2tanx/1 - tan^2x

 

[RivalryofTroll]

If you have cambridge then i believe they have a fairly solid explanation of these identities (if not wait for spiralflex ). You could also try this website http://www.sosmath.com/trig/trig.html however i find the font quite irritating haha. Hope this helps, and if you have any questions feel free to ask us!

Yeah, this is perfect! Don't worry about my posts, just explore the link!