Understanding First Derivatives and Relative Extrema

This video tutorial explains how to use the first derivative to determine if a function is increasing or decreasing and how to find relative extrema. It includes a review of major concepts, steps to find critical numbers, and examples using trigonometric functions. The video demonstrates how to calculate and analyze results to identify intervals of increase and decrease, as well as relative maxima and minima.

What is the primary focus of this video tutorial?

• Using the first derivative to determine increasing or decreasing functions and relative extrema

• Using integrals to find area under curves

• Using the second derivative to find concavity

• Using the first derivative to find absolute extrema

What indicates a relative minimum in a function?

• The function has a point of inflection

• The function changes from decreasing to increasing

• The function changes from increasing to decreasing

• The function remains constant

What is a critical number in the context of derivatives?

• A point where the function has a vertical asymptote

• A point where the function is not continuous

• A point where the second derivative is zero

• A point where the first derivative is zero or undefined

What is the first step in determining where a function is increasing or decreasing?

• Graph the function

• Find the critical numbers

• Find the second derivative

• Evaluate the function at endpoints

How do you determine the sign of the first derivative in each interval?

• By checking the continuity of the function

• By evaluating the second derivative

• By using a calculator to test values in each interval

• By finding the integral of the function

In the example problem, what are the critical numbers for the function 1/2 - sin(x)?

• x = π/6 and x = 5π/6

• x = 0 and x = π

• x = π/3 and x = 2π/3

• x = π/4 and x = 3π/4

What is the significance of the sign change in the first derivative?

• It indicates a vertical asymptote

• It indicates a discontinuity

• It indicates a relative maximum or minimum

• It indicates a point of inflection

What is the relative maximum value for the function at x = π/6?

• 5π/12 - √3/2

• π/12 + √3/2

• π/12 - √3/2

• 5π/12 + √3/2

What is the relative minimum value for the function at x = 5π/6?

• 5π/12 + √3/2

• 5π/12 - √3/2

• π/12 + √3/2

• π/12 - √3/2

How can you verify the calculated relative extrema?

• By checking the second derivative

• By comparing with a graph

• By finding the integral

• By evaluating the function at endpoints