Question

What is the phase shift of the function y = -cos(3(x+pie/2))-81. Right 3pie/22. Left pie/63. Right pie/2 4. Left pie/2

Answer 1

Option D is correct

`left\text{ }(\pi)/(2)`

Explanations:

The standard formula for expressing cosine functions is given as:

`y=cos(Bx+C)+D`

The phase shift is given as;

`phase\text{ shift}=-(c)/(b)`

Given the function

`\begin{gathered} y=-cos(3(x+(\pi)/(2)))-8 \\ y=-cos(3x+(3\pi)/(2))-8 \end{gathered}`

Compare with the general function

C = 3pi/2

B = 3

Find the phase shift

`\begin{gathered} Phase\text{ shift}=(-(3\pi)/(2))/(3) \\ Phase\text{ shift}=-(3\pi)/(6) \\ Phase\text{ shift}=-(\pi)/(2) \end{gathered}`

Since the phase shift is negative, hence the shift is to the left.