Trigonometry – Law of Sines

The Commander-in-TEACH debuts with our first lesson from the Oval Office! (Or perhaps, an amazing Oval Office studio set.) Here, President ObaMATH waxes poetic on the Law of Sines for Trigonometry. A simpler rule than the Law of Cosines, this law involves trigonometric ratios, in order to solve any triangle.

However, what isn't always so simple is the Ambiguous Case, which we cover here, using a unique method NOT done in the books. Great interaction by the POTUS's student cabinet members. YAY MATH!

Notable calculation errors in the video:
• at 21:32, the result should be 0.608, not 0.55
• at 22:01, thus, C=37.4°, not 33.5°
• at 22:28, the result should be 18.6°

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[Lexyvil]

You're the best Teacher I've seen online, and you'd also probably be the best to have in person too. If only all teachers were as interactive like that.

[neelrae]

My math teacher is really boring. never smile, forget about joke. I never seen like you, you are the best math teacher, .. math is awesome, cause it is really easy way to get marks. No worries about language problem, no worries about spelling problem, no worries about any long answer that really take time, only worries about formula and tricks. I'm not good at all but I love math.

[madisonday]

ObaMATH definitely fixed my life. My math grade has been saved. The book was too confusing!

[fionagepilango]

Thank you so much for making math easy! 🙌😀

[derekgreen]

Your an excellent teacher man. Just saying

[jonahsharpe]

Thank you. This is the sole reason why I am passing college based pre-calculus right now. :D

[ciphore]

Thank you! I have I quiz on this tomorrow and you couldn't upload this at a better time.

[nonofyourdamnbusinessleave]

Now you upload this after I dropped my class! 😩😔😭

[arelisavila]

You made a mistake! For the third problem showing Ambigous cases, sinC should be 0.6079 not .5526

[Grayson]

its crazy yet fascinating how students all around the world study the same thing, sending you lots of love from Abudhabi

[FreakMC]

Bruh I just found you again I loved watching your videos trying to understand math concepts! I'm sorta getting back into math after being out of school for 2 years and not really using it so maybe your videos can help me again.

[elybor]

Can you teach to all my teachers this way? life will much better

[jacquelinebroussard]

Ahhhh great teacher u are...I study parse syntax grammer..ur so good at putting it in easy term to innerstand.

[jaisonantony]

I am crazy over maths. I breath maths.

[marmite]

Because I'm a beginner, could you make this show it all step by step, so I know how it's all calculated please.

[jamesgraul]

I do not care for but I do love Yaymath!

[HarpreetSingh-xfio]

i can do it with yay Lots of love from india sir.... Namastay

[tatu]

Back in the old days before calculator invented, how do you solve for it or find out what numbers of, say, 15° sin, cos or tan ??

[britneedmonston]

No matter how many times I work it (on the 2nd case) I get sinC=0.6079 when I do 22sin124/30...help...

[DesignsbyCADPRO]

In a real problem in the world, how would know when to SSA would give you two angles?