The following summarizes the key characteristics of the equation of a sinusoidal function.
Any sinusoidal function can be expressed as either a sine function or a cosine function. A sinusoidal function of the form y = a sin b(x – c) + d or y = a cos b(x – c) + d has the following characteristics:
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The value of a is the amplitude.
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The value of b is the number of cycles in 360° or 2π radians.
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The period is
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The value of c indicates the horizontal translation that has been applied to the graph of y = sin x or y = cos x.
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The equation of the midline is y = d where
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The maximum value is d + a and the minimum value is d – a.
- The graph below represents a sine curve. In the graph of a cosine curve, c is the distance from the y-axis to the first maximum point.
In this Training Camp, you have identified the key characteristics of a sinusoidal function. Now, you will use these characteristics to match the graph of a sinusoidal function to its corresponding equation.