Question

Prove that, cos 60 = 32 cos 6 0 - 48 cos 4 0 +18 cos 4 0 - 1
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Answer 1

Step-by-step explanation:

Cos 6O = Cos(2*3O)

= 2Cos²3O - 1

= 2(4Cos³O - 3CosO)² - 1

= 2(16Cos 6O-24Cos⁴O+9Cos²O) - 1

= 32Cos 6O - 48Cos⁴O + 18Cos²O - 1