Please someone help me...

 see proof below

Step-by-step explanation:

Use the following Sum Identities:

cos (A + B) = cosA · cosB - sinA · sinB

sin (A + B) =  sinA · cos B - cosA · sinB

Use the Unit Circle to evaluate the following:

cos 30 = √3/2                            sin 30 = 1/2

cos 45 = √2/2                            sin 45 = √2/2

cos 120 = -1/2                             sin 120 = √3/2

cos 240 = -1/2                             sin 240 = -√3/2                        

cos 315 = √2/2                           sin 315 = -√2/2        

cos 330 = √3/2                          sin 330 = -1/2

Proof LHS → RHS

LHS = RHS:

No sheee

Step-by-step explanation:

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