### Scribe Post

Hello! This is Jaifel and it's my second scribe post. When we entered the class, Mr. K asked us to find the exact value of :

a. sin 100° cos 50°+ cos 100° sin 50°

we know that this is the sine law

sin (100° + 50°)

sin (150°)

1/2

b. cos π/3 cos π/12 + sin π/3 sin π/12

cos (π/3- cos π/12)

cos (4π/12- π/12)

a. sin 100° cos 50°+ cos 100° sin 50°

we know that this is the sine law

sin (100° + 50°)

sin (150°)

1/2

b. cos π/3 cos π/12 + sin π/3 sin π/12

*from our "dance" we know that this is the cosine law*

cos (π/3- cos π/12)

*and we also know that the sign changes**we then used a common denominator*cos (4π/12- π/12)

*and we get*(3π/12)*we reduce it as*cos (π/4)*which has a value of**He also asked us to prove that ...................*

d. cos(π+x)= cosx

cosπ cosx+ sinπsinx

-1 cosx -(0) sinx

-cosx

*PROOFS OF THE SUM AND DIFFERENCE IDENTITIES*

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