Chapter 10: Problem 15
Graph one cycle of the given function. State the period of the function. $$ y=\frac{1}{3} \tan (-2 x-\pi)+1 $$
Short Answer
Expert verified
The period of the function is \( \frac{\pi}{2} \).
Step by step solution
01
Identify the Tangent Function
The given function is \( y = \frac{1}{3} \tan(-2 x - \pi) + 1 \). It is a transformation of the tangent function \( y = \tan(x) \). The tangent function has a period of \( \pi \).
02
Determine the Period
The general form for the period of \( y = \tan(bx) \) is \( \frac{\pi}{|b|} \). Here, \( b = -2 \), so the period is \( \frac{\pi}{|-2|} = \frac{\pi}{2} \). This means one full cycle of the tangent function repeats every \( \frac{\pi}{2} \) units.
03
Account for Horizontal and Vertical Shifts
The function \( y = \frac{1}{3} \tan(-2 x - \pi) + 1 \) includes a horizontal phase shift and a vertical shift. The phase shift is determined by solving \( -2x - \pi = 0 \). Solving gives \( x = -\frac{\pi}{2} \), indicating a phase shift to the left by \( \frac{\pi}{2} \) units. The vertical shift is \(+1\), moving the entire graph up by 1 unit.
04
Graph the Function
To graph, start by plotting the phase-shift point \((x = -\frac{\pi}{2}, y = 1)\). From there, since the period is \( \frac{\pi}{2} \), plot asymptotes at \( x = -\frac{\pi}{2} \) and \( x = 0 \), and symmetric points around them based on the tangent shape. Use \( y = 1 \) as the new center line, so peaks and troughs will occur \( \frac{1}{3} \) unit above and below this line.
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Understanding the Tangent Function
The tangent function, represented by the equation \( y = \tan(x) \), is a fundamental trigonometric function renowned for its periodic oscillating behavior. Unlike the sine and cosine functions which are known for their smooth and continuous wave-like patterns, the tangent function exhibits a different pattern, characterized by intersecting the x-axis at regular intervals and having vertical asymptotes where the function is undefined.
Some unique characteristics of the tangent function include:
Some unique characteristics of the tangent function include:
- Intersects the x-axis at integer multiples of \( \pi \).
- The function has no maximum or minimum points, as its values extend to positive and negative infinity near its vertical asymptotes.
- Unlike sine and cosine, it is an odd function, meaning it is symmetrical about the origin.
Determining the Period of a Function
The period of a trigonometric function is the interval over which the function's pattern repeats. For the basic tangent function \( y = \tan(x) \), this period is \( \pi \), reflecting how it repeats its vertical cycloid path every \( \pi \) units along the x-axis.
To find the period of a transformed tangent function of the form \( y = \tan(bx) \), use the formula:
This reduced period signifies that the rapid oscillating cycle of the tangent occurs twice as often compared to the standard function, completing a full cycle every \( \frac{\pi}{2} \) units.
To find the period of a transformed tangent function of the form \( y = \tan(bx) \), use the formula:
- Period = \( \frac{\pi}{|b|} \), where b is the coefficient of x.
This reduced period signifies that the rapid oscillating cycle of the tangent occurs twice as often compared to the standard function, completing a full cycle every \( \frac{\pi}{2} \) units.
Graph Transformations and Their Effects
Graph transformations involve modifying the basic graph of a function to produce shifts, stretches, shrinks, or reflections. When examining \( y = \frac{1}{3} \tan(-2x - \pi) + 1 \), we see multiple transformations applied to the standard tangent function.
- Amplitude Modification: The coefficient \( \frac{1}{3} \) scales the tangent values, decreasing the steepness of rise and fall.
- Horizontal Phase Shift: Determined by solving the equation \( -2x - \pi =0 \), results in a shift to the left by \( \frac{\pi}{2} \) units.
- Vertical Shift: Occurs by adding \(+1\), lifting the entire graph up by 1 unit, thereby adjusting the centerline of the oscillation.