Can you explain the amplitude, period, and phase shift of the function f(x) = 3 cos(4x) + 6?

Understanding Amplitude, Period, and Phase Shift

The function you provided is f(x) = 3 cos(4x) + 6, which is a transformation of the basic cosine function. Let’s break it down step-by-step to identify its amplitude, period, and phase shift.

1. Amplitude

Amplitude in a cosine function describes the height of the wave from its center line to its peak. In the equation  f(x) = A cos(Bx) + D, A represents the amplitude.

For our function:

  • A = 3

Thus, the amplitude is 3. This means the wave will oscillate 3 units above and below its center line.

2. Period

The period of a cosine function is determined by the B value in the equation, which affects how frequently the wave repeats. The formula for calculating the period is:

Period = (2π) / |B|

In our case:

  • B = 4

Plugging in the value:

Period = (2π) / |4| = π/2

Thus, the period of the function is π/2, indicating that the wave completes one full cycle in that interval.

3. Phase Shift

Phase shift refers to a horizontal shift in the graph of the function. If there’s a horizontal translation, it will typically be represented in the function as f(x) = A cos(B(x – C)) + D, where C indicates the phase shift. In your function f(x) = 3 cos(4x) + 6, there’s no additional term inside the cosine function that would shift it to the left or right.

This means the phase shift is:

  • Phase Shift = 0

So, the graph of the cosine function has no horizontal translation and begins at the origin of the cosine function.

Conclusion

In summary, for the function f(x) = 3 cos(4x) + 6:

  • Amplitude: 3
  • Period: π/2
  • Phase Shift: 0

Understanding these components helps to visualize and analyze the behavior of the cosine function as it oscillates!

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