Hey again,
Yes i have some problems with questions about Trig. Functions again and im planning to make it a regular thing if posting on the forum is my last resort if you guys dont mind. Here are the questions:
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cos ( pi /4 + x ) is the identity of 1 / root 2 (cos x - sin x)
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cos (a + b ) . cos (a + b) is the identity of cos squared a - sin squared b
Can somebody assist me?