Question

Express the following as afunction of a single angle.cos 60° cos 45º – sin 60° sin 45°cos[ ? ]

Answer 1

The Solution.

Step 1:

We shall find the single angle by compound angles formula.

`\cos 60^o\cos 45^o-\sin 60^o\sin 45^o=\cos (60+45)^o=\cos 105^o`

Thus, the required angle is 105 degrees

Step 2:

Presentation of the Answer.

So, the correct answer is 105 degrees.