Question

What is the period of the graph of y = 2 cos (7x)+ 3?O A. 2O B.klaalO C.O D. 4

Answer 1

Given the following function:

`\text{ y = 2cos(}(\pi)/(2)x)\text{ + 3}`

We will be using the standard formula aCos (bx - c) + d to find the variables used to find the period.

We get,

aCos (bx - c) + d = 2 cos (π/2x) + 3

a = 2

b = π/2

c = 0

d = 3

Finding the period, we will be using the following formula:

`\text{ Period = }(2\pi)/(b)`

We get,

`\text{ Period = }(2\pi)/(b)`
`\text{ = }(2\pi)/((\pi)/(2))`
`\text{ = 2(}\pi)\text{ x }(2)/((\pi))`
`\text{ = 2 x 2}`
`\text{ Period = 4}`

Therefore, the period of y = 2 cos (π/2x) + 3 is 4. The answer is letter D.