Trigonometry Identities: sin(-x) = - sin(x) and cos(-x) = cos(x)

in MES Science16 days ago (edited)

In this video I prove the two identities, sin(-x) = - sin(x) and cos(-x) = cos(x), which show that cosine is an even function while sine is an odd function.

Download video notes:!As32ynv0LoaIid9STvHbTf9TjgcoCw?e=uyOUFH

Watch video on:

View Video Notes Below!

Download these notes: Link is in video description.
View these notes as an article:
Subscribe via email:
Donate! :)
Buy MES merchandise!
More links:
Follow my research in real-time on my MES Links Telegram:
Subscribe to MES Truth:

Reuse of my videos:

  • Feel free to make use of / re-upload / monetize my videos as long as you provide a link to the original video.

Fight back against censorship:

  • Bookmark sites/channels/accounts and check periodically
  • Remember to always archive website pages in case they get deleted/changed.

Recommended Books:

Join my forums!

Follow along my epic video series:

NOTE #1: If you don't have time to watch this whole video:

Browser extension recommendations:

Trigonometry Identities

Trig Identities - sin-y = -siny Resized AI.jpg

sin(-ϴ) = -sin(ϴ) and cos(-ϴ) = cos(ϴ)




You prove once again that I'm an ignoramus, lol, but when I saw how easily my daughter solves problems in trigonometry, I became part of something bigger than I am :)
I absorb information more easily if I understand how to apply it in real life. How can knowing about the even and odd of these functions help me?

haha good to hear you are feeling more inclined to learn mathematics! Math has lots of applications in the real world, but fundamentally it is just a mental exercise of logic. Chess or other similar board games are other good examples of mental workouts, which have indirect benefits to one's mental well being in the same way that lifting heavy rocks (aka physical exercise) has to one's physical well being.

Regarding even and odd functions, unless you are dealing with modeling electromagnetic waves, I'm not sure how they can help you directly. But in terms of the underlying logic, it is just an exercise in pattern recognition, which can indirectly help you notice patterns in your everyday social or work setting.

I absolutely agree with you that this material is highly specialized and is applied mathematics, for application in a certain field of activity, it is not clear why children are tormented by this at school? If they are interested in mathematics, they will love it, like chess, which not everyone loves :)

Congratulations, @stem-shturm You Successfully Shared 0.100 WINEX With @mes.
You Earned 0.100 WINEX As Curation Reward.
You Utilized 1/1 Successful Calls.


Contact Us : WINEX Token Discord Channel
WINEX Current Market Price : 0.091

Swap Your Hive <=> Swap.Hive With Industry Lowest Fee (0.1%) : Click This Link
Read Latest Updates Or Contact Us

I think it comes down to perspective and also what the purpose of school is haha Math was the easy part for me, social studies / history / reading / writing was the hard part! One thing I wish every school teaches is financial planning / literacy, taxes, and citizenship rights / responsibilities. Interestingly, I started my math channel because I didn't like the way math was taught in school haha

Maybe they teach well. but not everyone needs it so deeply :)

Thanks for your contribution to the STEMsocial community. Feel free to join us on discord to get to know the rest of us!

Please consider delegating to the @stemsocial account (85% of the curation rewards are returned).

You may also include @stemsocial as a beneficiary of the rewards of this post to get a stronger support.