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Mar 8 2016 12:43am
How do you graph the derivative when given the graph of the initial equation but doesn't state the equation?
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Mar 8 2016 02:22am
The derivative is the slope of the graph at any given point. If you have a graph that is full of straight line segments, the derivative of that graph will be a bunch of horizontal line segments with open circle endpoints. For example if part of graph was a line segment from (0,0) to (2,2) we would know the slope between 0 and 2 on the x axis would be 1. So, the graph of the derivative between 0 and 2 would be a horizontal line segment with open endpoints at y = 1 from 0 to 2.

This post was edited by timmayX on Mar 8 2016 02:23am
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Mar 8 2016 04:09am
Quote (Hirokiy @ Mar 7 2016 11:43pm)
How do you graph the derivative when given the graph of the initial equation but doesn't state the equation?


or you could think of a function that replicates what the graph shows, take it's derivative, then graph it.
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Mar 8 2016 10:40am
Quote (Hirokiy @ Mar 8 2016 07:43am)
How do you graph the derivative when given the graph of the initial equation but doesn't state the equation?


It's impossible, unless :
- you know with an infinite precision the position of any point of the initial graph (which in turns is almost the same as knowing the equation)
- you know something extra about the graph regularity, that allows you to give a valid approximation of the derivative.

See that counter-example :

f ( x ) = 100 + 0.01. cos (10000.x )

Show the graph of f : it appears like an horizontal straight line. You might believe that its derivative is zero.
Now check with the given equation, and see what happens.
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Mar 8 2016 05:50pm
feanur is correct (of course), but there is lots of shitty math questions out there. So if you are given what looks like the graph of x^2 and they ask you for the derivative, write down 2x.
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