Table of contents
- 0. Functions7h 52m
- Introduction to Functions16m
- Piecewise Functions10m
- Properties of Functions9m
- Common Functions1h 8m
- Transformations5m
- Combining Functions27m
- Exponent rules32m
- Exponential Functions28m
- Logarithmic Functions24m
- Properties of Logarithms34m
- Exponential & Logarithmic Equations35m
- Introduction to Trigonometric Functions38m
- Graphs of Trigonometric Functions44m
- Trigonometric Identities47m
- Inverse Trigonometric Functions48m
- 1. Limits and Continuity2h 2m
- 2. Intro to Derivatives1h 33m
- 3. Techniques of Differentiation3h 18m
- 4. Applications of Derivatives2h 38m
- 5. Graphical Applications of Derivatives6h 2m
- 6. Derivatives of Inverse, Exponential, & Logarithmic Functions2h 37m
- 7. Antiderivatives & Indefinite Integrals1h 26m
- 8. Definite Integrals4h 44m
- 9. Graphical Applications of Integrals2h 27m
- 10. Physics Applications of Integrals 2h 22m
0. Functions
Introduction to Trigonometric Functions
Problem 1.48
Textbook Question
Solving equations Solve each equation.
sin² 2Θ = 1/2, -π/2 ≤ Θ ≤ π/2

1
Step 1: Recognize that the equation is in the form of \( \sin^2(2\Theta) = \frac{1}{2} \). To solve for \( \Theta \), first take the square root of both sides to get \( \sin(2\Theta) = \pm \frac{1}{\sqrt{2}} \).
Step 2: Recall that \( \sin(2\Theta) = \pm \frac{1}{\sqrt{2}} \) corresponds to angles where the sine function equals \( \frac{1}{\sqrt{2}} \) or \( -\frac{1}{\sqrt{2}} \). These angles are \( \frac{\pi}{4}, \frac{3\pi}{4}, -\frac{\pi}{4}, \) and \( -\frac{3\pi}{4} \).
Step 3: Set \( 2\Theta = \frac{\pi}{4}, \frac{3\pi}{4}, -\frac{\pi}{4}, \) and \( -\frac{3\pi}{4} \) to find the possible values of \( 2\Theta \).
Step 4: Solve for \( \Theta \) by dividing each angle by 2. This gives \( \Theta = \frac{\pi}{8}, \frac{3\pi}{8}, -\frac{\pi}{8}, \) and \( -\frac{3\pi}{8} \).
Step 5: Verify that each solution for \( \Theta \) falls within the given interval \( -\frac{\pi}{2} \leq \Theta \leq \frac{\pi}{2} \).

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Trigonometric Functions
Trigonometric functions, such as sine, cosine, and tangent, relate angles to ratios of sides in right triangles. The sine function, specifically, gives the ratio of the length of the opposite side to the hypotenuse. Understanding these functions is crucial for solving equations involving angles, as they provide the foundational relationships needed to manipulate and solve trigonometric equations.
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Inverse Trigonometric Functions
Inverse trigonometric functions, such as arcsin, arccos, and arctan, are used to find angles when the values of the trigonometric functions are known. For example, if sin(Θ) = 1/2, then Θ can be found using arcsin(1/2). These functions are essential for solving equations where the angle is the unknown, allowing us to determine the angle that corresponds to a given sine, cosine, or tangent value.
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Periodic Nature of Trigonometric Functions
Trigonometric functions are periodic, meaning they repeat their values in regular intervals. For sine, the period is 2π, which implies that sin(Θ) = sin(Θ + 2πk) for any integer k. This periodicity is important when solving trigonometric equations, as it allows for multiple solutions within a specified range, such as the interval -π/2 ≤ Θ ≤ π/2 in the given problem.
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