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MATHEMATICS - THEORY
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Slope of a line
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Slope of a Line
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The slope of a line is denoted by m and can
be determined with two points: A(x1,y1) and B(x2,
y2).
It can also be determined by:
in which α is the smallest positive
angle from the x axis to the line. When the line is horizontal, m =
0 and when the line is vertical, m is infinity or not defined.
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Tangent
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Slope of a Curve |
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Suppose curve C (f(x)) is a function of x, the tangent
line of the curve C at point A is desired.
Now, consider B point where x2 is not equal
to x1, the slope of AB is:
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Tangent of a Curve |
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Let point B approaches A along the curve C by
letting x2 approaches x1, when x2 - x1 is
small enough, the slope of AB will overlap with its tangent line at point
A.Thus, the tangent at point A can be written as:
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Tangent Example - Velocity
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Velocity is a good example of a tangent line.
Normally, the distance s is a function of time t. The velocity of a time
interval
is
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Velocity of any Function
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On a graph of distance plotted as a function
of time, the tangent (instantaneous velocity) is:
Therefore, the instantaneous velocity at time t, is equal to the slope
of the tangent line at point A. |
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