In Exercises 12–18, solve each equation on the interval [0, 2𝝅). Use exact values where possible or give approximate solutions correct to four decimal places. 2 sin² x + cos x = 1
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
Linear Trigonometric Equations
Problem 6.RE.39
Textbook Question
Solve each equation over the interval [0, 2π). Write solutions as exact values or to four decimal places, as appropriate.
tan x = cot x
Verified step by step guidance1
Recall the definitions of tangent and cotangent: \(\tan x = \frac{\sin x}{\cos x}\) and \(\cot x = \frac{\cos x}{\sin x}\).
Set the equation \(\tan x = \cot x\) and rewrite it using the definitions: \(\frac{\sin x}{\cos x} = \frac{\cos x}{\sin x}\).
Cross-multiply to eliminate the fractions: \(\sin^2 x = \cos^2 x\).
Use the Pythagorean identity \(\sin^2 x + \cos^2 x = 1\) to express one function in terms of the other, or recognize that \(\sin^2 x = \cos^2 x\) implies \(\sin^2 x - \cos^2 x = 0\).
Rewrite the equation as \(\sin^2 x - \cos^2 x = 0\), which can be factored or recognized as \(\cos 2x = 0\). Solve \(\cos 2x = 0\) over the interval \([0, 2\pi)\) to find the values of \(x\).
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Play a video:
0 Comments
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Relationship Between Tangent and Cotangent
Tangent and cotangent are reciprocal trigonometric functions, where tan(x) = sin(x)/cos(x) and cot(x) = cos(x)/sin(x). Understanding their relationship helps in transforming or equating expressions involving these functions.
Recommended video:
Introduction to Cotangent Graph
Solving Trigonometric Equations
Solving equations like tan(x) = cot(x) involves manipulating the equation to find values of x that satisfy it within a given interval, often by using identities or rewriting functions in terms of sine and cosine.
Recommended video:
How to Solve Linear Trigonometric Equations
Interval and General Solutions in Trigonometry
Trigonometric functions are periodic, so solutions repeat every 2π. When solving over [0, 2π), it is important to find all unique solutions within this interval, considering the periodicity and domain restrictions.
Recommended video:
Fundamental Trigonometric Identities
Related Videos
Related Practice
Textbook Question
421
views
