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 Integrals3h 25m
3. Techniques of Differentiation
Derivatives of Trig Functions
Problem 3.5.55b
Textbook Question
An object oscillates along a vertical line, and its position in centimeters is given by y(t) = 30(sint - 1), where t ≥ 0 is measured in seconds and y is positive in the upward direction.
Find the velocity of the oscillator, v(t) =y′(t).

1
To find the velocity of the oscillator, we need to differentiate the position function y(t) = 30(sin(t) - 1) with respect to time t.
Recall that the derivative of sin(t) with respect to t is cos(t). Therefore, apply the derivative to each term in the function y(t).
The derivative of the constant term -30 is 0, since constants do not change with respect to t.
Differentiate the term 30sin(t) using the chain rule. The derivative of 30sin(t) is 30cos(t).
Combine the derivatives to get the velocity function v(t) = y'(t) = 30cos(t).

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Differentiation
Differentiation is a fundamental concept in calculus that involves finding the derivative of a function. The derivative represents the rate of change of the function with respect to its variable. In this context, differentiating the position function y(t) = 30(sin(t) - 1) will yield the velocity function v(t), which describes how the position of the object changes over time.
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Trigonometric Functions
Trigonometric functions, such as sine and cosine, are essential in modeling periodic phenomena, including oscillations. The sine function, in particular, describes the oscillatory behavior of the object in this problem. Understanding the properties of these functions, including their ranges and periodicity, is crucial for analyzing the motion of the oscillator.
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Introduction to Trigonometric Functions
Velocity
Velocity is a vector quantity that indicates the rate of change of an object's position with respect to time. In this scenario, the velocity function v(t) is derived from the position function y(t) by differentiation. It provides insight into how fast and in which direction the object is moving along the vertical line, which is vital for understanding its oscillatory motion.
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