In Exercises 83–94, use a right triangle to write each expression as an algebraic expression. Assume that x is positive and that the given inverse trigonometric function is defined for the expression in x. ___ sec (sin⁻¹ x/√x²+4)
Table of contents
- 0. Review of College Algebra4h 45m
- 1. Measuring Angles40m
- 2. Trigonometric Functions on Right Triangles2h 5m
- 3. Unit Circle1h 19m
- 4. Graphing Trigonometric Functions1h 19m
- 5. Inverse Trigonometric Functions and Basic Trigonometric Equations1h 41m
- 6. Trigonometric Identities and More Equations2h 34m
- 7. Non-Right Triangles1h 38m
- 8. Vectors2h 25m
- 9. Polar Equations2h 5m
- 10. Parametric Equations1h 6m
- 11. Graphing Complex Numbers1h 7m
5. Inverse Trigonometric Functions and Basic Trigonometric Equations
Inverse Sine, Cosine, & Tangent
Problem 101
Textbook Question
The graphs of y = sin⁻¹ x, y = cos⁻¹ x, and y = tan⁻¹ x are shown in Table 2.8. In Exercises 97–106, use transformations (vertical shifts, horizontal shifts, reflections, stretching, or shrinking) of these graphs to graph each function. Then use interval notation to give the function's domain and range. h(x) = −2 tan⁻¹ x
Verified step by step guidance1
Identify the base function given, which is the inverse tangent function \(y = \tan^{-1} x\). Recall that its standard domain is \((-\infty, \infty)\) and its range is \(\left(-\frac{\pi}{2}, \frac{\pi}{2}\right)\).
Analyze the transformation applied to the base function. The function is \(h(x) = -2 \tan^{-1} x\), which involves two transformations: a vertical stretch by a factor of 2 and a reflection about the x-axis (due to the negative sign).
Apply the vertical stretch and reflection to the range of \(\tan^{-1} x\). Since the original range is \(\left(-\frac{\pi}{2}, \frac{\pi}{2}\right)\), multiplying by -2 will stretch the range by 2 and flip it, so the new range will be \(\left(-2 \times \frac{\pi}{2}, -2 \times -\frac{\pi}{2}\right)\).
Note that the domain of \(\tan^{-1} x\) is all real numbers, and since the transformation only affects the output (y-values), the domain of \(h(x)\) remains \((-\infty, \infty)\).
Summarize the domain and range in interval notation after applying the transformations, and sketch the graph by reflecting and stretching the original \(\tan^{-1} x\) graph accordingly.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
10mPlay a video:
0 Comments
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Inverse Trigonometric Functions
Inverse trigonometric functions like sin⁻¹x, cos⁻¹x, and tan⁻¹x return the angle whose trigonometric ratio equals x. They have specific domains and ranges, for example, tan⁻¹x has domain all real numbers and range (−π/2, π/2). Understanding these functions is essential for graphing and interpreting their transformations.
Recommended video:
Introduction to Inverse Trig Functions
Graph Transformations
Graph transformations include vertical and horizontal shifts, reflections, stretches, and shrinks. For h(x) = −2 tan⁻¹ x, the negative sign reflects the graph across the x-axis, and the factor 2 vertically stretches it by a factor of 2. Recognizing how these changes affect the graph helps in sketching and analyzing the function.
Recommended video:
Introduction to Transformations
Domain and Range of Transformed Functions
The domain of inverse trig functions often remains unchanged under vertical transformations, but the range changes according to vertical stretches or reflections. For h(x) = −2 tan⁻¹ x, the domain is all real numbers, while the range is the original range (−π/2, π/2) scaled and reflected, resulting in (−π, π). Using interval notation accurately describes these sets.
Recommended video:
Domain and Range of Function Transformations
Related Videos
Related Practice
Textbook Question
820
views
