Question

Difficulty: EasyGraphs of Trigonometric Functions

What is the period of the function f(x)=tan(3x)f(x) = \tan(3x)?

  1. A
    2π3\frac{2\pi}{3}
  2. B
    3π3\pi
  3. π3\frac{\pi}{3}Answer
  4. D
    π\pi
  5. E
    33

Answer

The period of the function is π3\frac{\pi}{3}.
The parent function y=tan(x)y = \tan(x) has a standard period of π\pi. To find the period of a transformed tangent function of the form y=tan(Bx)y = \tan(Bx), the standard period must be divided by the coefficient of xx, yielding πB\frac{\pi}{|B|}. Substituting B=3B = 3 gives π3\frac{\pi}{3}.

Step-by-Step Solution

1
Determine the standard period of the parent function.
The parent function is the tangent function, y=tan(x)y = \tan(x), which has a standard period of π\pi.
The tangent function completes one full cycle of its graph between π2-\frac{\pi}{2} and π2\frac{\pi}{2}.
2
Identify the horizontal compression/stretch coefficient from the given equation.
In f(x)=tan(3x)f(x) = \tan(3x), the coefficient of xx is B=3B = 3.
This coefficient determines how many cycles occur in a standard interval.
3
Calculate the period using the formula for the tangent function.
Period = πB=π3\frac{\pi}{|B|} = \frac{\pi}{3}.
Dividing the standard period of π\pi by the absolute value of the coefficient BB gives the compressed period of the transformed function.

Key Concept

The period of a transformed tangent function y=tan(Bx)y = \tan(Bx) is given by πB\frac{\pi}{|B|}.
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