Question

Find values of a and b such that the function y=sinθ can be expressed as y=a cos (θ+b) .

Answer 1

Answer:
`a=1, b=-(\pi)/(2)`

Explanation:

Note that
`\sin \theta=\cos \left((\pi)/(2)-\theta \right)`.

Since the cosine function is an even function, we can say that
`\sin \theta =\cos \left(\theta-(\pi)/(2) \right)`.

Therefore, we can choose
`a=1, b=-(\pi)/(2)`.