Trigonometric Identities to Evaluate Expressions - Part 1 of 2 (Sum and Difference Identity)

In this example I use a sum identity to evaluate sin(75 degrees) and tan (pi/12).

[Brianww]

Great video! What makes your videos remarkably better than most other instructional videos is the way that you narrate your thought process while you work out the problem. The way you seamlessly transition from your thoughts when interjecting a key concept or common mistake is brilliant. Thank you so much for selflessly helping those in need of assistance or those who strive to better appreciate the elegance of what is mathematics.

[stephenkocis]

love you so much Patrick, because of you I ALWAYS GET GOOD GRADES

[ayshab]

I'm confused, my teacher showed us as cos 30cos45+sin30sin45, is that wrong because I'm doing a worksheet and I'm not getting the same answer as it

[AayahPorter]

So detailed, so helpful. I'm extremely grateful for you videos!

[ielizabethm]

Things looks so much easier when you teach. I needed some refreshment from university calculus so this video was perfect to review on.

[theinternetguy]

Good video. Keep up the good work. This was very helpful.

[Mumfin]

You da man. I'm gonna have to donate more money soon.

[henrygalvan]

wait you know in the beginning of the tan function. couldn't you just have converted radiant to decimal 180/12=15

[angelgacusan]

this help me a lot OMG THANK YOU!!!! 😭😄

[creampuff]

God bless your wonderful soul Patrick!

[ajayalmighty]

Do you plan on making any videos about differential equations?

[Javynoza]

Patrick why would we multiply by the the conjugate rather than the denominator? I’m so confused.

[krystalkeene]

But I do LOVE these videos. They help so much, thank you ! 

[YoUrViDeOSuCksAsSXD]

I wanna thank you for getting me through year 9 And 10 maths, but now I'm on my VCE course for foundation maths, ( counting how many pepperonis are on a pizza for fractions) so I guess I don't need to learn trig and algebra anymore haha

[Rumasila]

You went from "alright" to "ok" xd
Btw, thnx for the info! Really helped!

[Zzznmop]

4:45 can you use common denominator to add root2/4+root6/4=root8/4