Basic Differentiation Rules and Rates of Change12105. Velocity Verify that the average velocity over the time interval [t0−Δt,t0+Δt] is the same as the instantaneous velocity at t=t0 for the position function
Q. Basic Differentiation Rules and Rates of Change12105. Velocity Verify that the average velocity over the time interval [t0−Δt,t0+Δt] is the same as the instantaneous velocity at t=t0 for the position function
Define Average Velocity Formula: To find the average velocity, we need to use the formula: Average Velocity = Final time−Initial timePosition at final time−Position at initial time.
Calculate Average Velocity Interval: Let's denote the position function as s(t). The average velocity over the interval [t0−Δt,t0+Δt] is (t0+Δt)−(t0−Δt)s(t0+Δt)−s(t0−Δt).
Simplify Denominator: Simplify the denominator: (t0+Δt)−(t0−Δt)=2Δt.
Plug in Simplified Denominator: Now, plug in the simplified denominator into the average velocity formula: Average Velocity = 2Δts(t0+Δt)−s(t0−Δt).
Find Instantaneous Velocity: To find the instantaneous velocity at t=t0, we need to take the derivative of the position function s(t) with respect to time t and then evaluate it at t=t0.
Apply Mean Value Theorem: Let's denote the derivative of s(t) as s′(t). The instantaneous velocity at t=t0 is s′(t0).
Approach Instantaneous Velocity: If the position function s(t) is differentiable, then by the Mean Value Theorem, there exists some point c in (t0−Δt,t0+Δt) such that s′(c) is equal to the average velocity over that interval.
Equivalence of Average and Instantaneous Velocity: Since we are looking at the interval shrinking to a single point t0, as Δt approaches 0, the point c approaches t0, and thus the average velocity approaches the instantaneous velocity at t=t0.
Equivalence of Average and Instantaneous Velocity: Since we are looking at the interval shrinking to a single point t0, as Δt approaches 0, the point c approaches t0, and thus the average velocity approaches the instantaneous velocity at t=t0.Therefore, the average velocity over the interval [t0−Δt,t0+Δt] is the same as the instantaneous velocity at t=t0 for the position function s(t).
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