What are the period range and amplitude of the cosine function y = 3cos(4x)?

The cosine function is a periodic function that oscillates between -1 and 1. To analyze the specific function given, y = 3cos(4x), we can break it down into its components: amplitude, period, and range.

Amplitude

The amplitude of a cosine function y = A * cos(Bx) is determined by the coefficient A. In this case, the amplitude is:

  • Amplitude = |A| = |3| = 3

This means the function will reach a maximum value of 3 and a minimum value of -3.

Period

The period of a cosine function is calculated using the formula:

Period = (2π) / |B|

For our function, B = 4, so the period is:

  • Period = (2π) / |4| = π / 2

This means the function completes one full cycle every π/2 units along the x-axis.

Range

The range of the cosine function defines the values that y can take. Since we know the amplitude is 3, the range for the function y = 3cos(4x) can be determined as:

  • Range: [-3, 3]

This indicates that the values of y will vary from -3 to 3.

Summary

To summarize:

  • Amplitude: 3
  • Period: π/2
  • Range: [-3, 3]

This gives you a complete understanding of the behavior of the cosine function y = 3cos(4x). Happy studying!

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