This week our wiki project is to improve some of the trigonometry pages on the site. Thanks to your contributions from previous wiki weekend parties, we have collectively made hundreds of edits to wiki pages and helped Brilliant's 1,000,000+ FB followers learn, collaborate, and solve problems together!

To participate, just jump in and write something on one of the following pages, and then leave a comment to let us know that you contributed. To guide you in crafting the wikis, we have included section outlines, identities in need of proofs, and examples in need of solutions. We need your help to replace the many "???" throughout these wikis with your brilliant proofs and solutions. Or feel free to add a new section or submit your own example. Every contribution helps!

- Basic Trigonometric Functions
- Sine and Cosine Graphs
- Symmetry in Trigonometric Graphs
- Sum to Product Trigonometric Identities
- Trigonometric Power Reduction Identities

Thanks for your help!

## Comments

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TopNewestI answered the unanswered questions in Basic Trigonometric Functions. – Omkar Kulkarni · 1 year, 5 months ago

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– Pranjal Jain · 1 year, 5 months ago

I have an advice. Use degrees instead of radians. The page is for newbies who might not have studied about radians. Thanks. \(\ddot\smile\)Log in to reply

– Omkar Kulkarni · 1 year, 5 months ago

Oh okay! Good suggestion, thanks.Log in to reply

– Victor Loh · 1 year, 5 months ago

Thanks! Keep it up!Log in to reply

Is there a sum to product identity for \(\tan x+\tan y\)? The only one I can think of is \((\tan(x+y))(1-\tan x\tan y)\), or maybe something like \(\frac{\sin(x+y)}{\cos x\cos y}\).

Oh, and, could someone please give me a link to the wiki from where I can start studying matrices? Can't find it. Thanks :) – Omkar Kulkarni · 1 year, 5 months ago

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We haven't started on the matrices skills as yet, because we rather focus on filling out existing areas first. – Calvin Lin Staff · 1 year, 5 months ago

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– Omkar Kulkarni · 1 year, 5 months ago

Okay thanks! Yeah, I can get to the formula.Log in to reply

– Pranjal Jain · 1 year, 5 months ago

That should be \(\tan(x+\color{red}{y})(1-\tan x\tan y)\)Log in to reply

– Calvin Lin Staff · 1 year, 5 months ago

Thanks! fixed.Log in to reply

sir, can we add wiki on INVERESE TRIGONOMETRY also??? – Aditya Kumar · 1 year, 5 months ago

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functions, identities and graphs(this one is empty). So you don't need to make new Wikis (unless it's a completely new subtopic you wanna write about), you can go through these and add any knowledge they lack. – Omkar Kulkarni · 1 year, 5 months ago

There are already pages on inverse trigonometry,Log in to reply

– Pranjal Jain · 1 year, 5 months ago

Sure. Add a wiki on any topic you like. \(\ddot\smile\)Log in to reply

– Aditya Kumar · 1 year, 5 months ago

Yeah sure.....I'll collect all the required wikis for the topic and post it tomorrowLog in to reply

– Calvin Lin Staff · 1 year, 5 months ago

Thanks! I look forward to reading your contributions :)Log in to reply

– Aditya Kumar · 1 year, 5 months ago

Sir, i've added a wiki. can u see if its fineLog in to reply