See Jiayang's answer to Amanda's Secondary 4 A Maths question

Jiayang's answer to Amanda's Secondary 4 A Maths question.

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Date Posted: 5 years ago

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Amanda

Amanda

5 years ago

how did u get cos6x + cos2x?

Jiayang

Jiayang

5 years ago

That's via the factor formula...
cosA + cosB = 2cos[(A+B)/2]cos(A-B)/2]