Question

Difficulty: MediumGraphs of Trigonometric Functions

Which of the following values represents the period, in radians, of the trigonometric function f(x)=3tan(23xπ6)+5f(x) = 3 \tan\left(\frac{2}{3}x - \frac{\pi}{6}\right) + 5?

  1. 3π2\frac{3\pi}{2}Answer
  2. B
    3π3\pi
  3. C
    2π3\frac{2\pi}{3}
  4. D
    π6\frac{\pi}{6}
  5. E
    3π4\frac{3\pi}{4}

Answer

The period of the given tangent function is 3π2\frac{3\pi}{2} radians.
The parent function y=tan(x)y = \tan(x) repeats every π\pi radians. For a function in the form f(x)=Atan(BxC)+Df(x) = A \tan(Bx - C) + D, the horizontal scale factor BB alters the period according to Period=πB\text{Period} = \frac{\pi}{|B|}. With B=23B = \frac{2}{3}, dividing π\pi by 23\frac{2}{3} gives 3π2\frac{3\pi}{2}.

Step-by-Step Solution

1
Identify the standard form of the transformed tangent function and its parameters.
For f(x)=Atan(BxC)+Df(x) = A \tan(Bx - C) + D, the coefficient of xx is B=23B = \frac{2}{3}.
The horizontal stretch/compression factor BB determines the period of the function.
2
Apply the period formula for the tangent function.
\text{Period} = \frac{\pi}{|B|} = \frac{\pi}{\frac{2}{3}} = \frac{3\pi}{2}
Unlike sine and cosine functions which have a fundamental period of 2π2\pi, the parent tangent function y=tan(x)y = \tan(x) has a period of π\pi radians.

Key Concept

Period of Transformed Tangent Functions
Estimated Time:1m 0s
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