Cosine law proof

Proof of the cosine rule (aka the law of cosines) using Pythagoras' theorem and cos = adj/hyp.

[THaWoM]

Let me know what maths topics confuse you!

[hugodesrosiers-plaisance]

Understanding the underlying proofs really cements the understanding of the resulting equations. Thank you for this.

[emma.b.d]

Thank you mam l pray that people subscribe to your channel ❤❤

[seroujghazarian]

Or, you could use the fact that addition is commutative and put h^2 near c^2×cos^2(A) to have h^2+c^2×cos^2(A), which is c^2, just a suggestion.

[WiIfredOwen]

Wonderful explanation of cosine proof.

[mrmoinn]

Great video! It didn't go on any longer than it had to.

[eipimath]

Thanks for sharing! I posted a short video on deriving the law of cosines, It should apply for all angles (acute, obtuse, reflex, negative). Hope to get your thoughts.