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#1 2015-12-27 10:24:20
- tyuighp
- Member
- Registered: 2015-12-04
- Posts: 12
Find the equations
Find the equations of the tangent line to
f(x)=3x^4-4x^3
at two different points
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#2 2015-12-27 11:07:10
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Find the equations
What two points? Are they on the curve?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#3 2015-12-28 09:33:57
- tyuighp
- Member
- Registered: 2015-12-04
- Posts: 12
Re: Find the equations
hi bobbym
yes they are on the curve
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#4 2015-12-28 13:14:24
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Find the equations
What points are they?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#5 2015-12-31 10:09:57
- tyuighp
- Member
- Registered: 2015-12-04
- Posts: 12
Re: Find the equations
Find the equation of the line that touches the curve
at two different points.Solution
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#6 2016-01-02 15:28:23
- Nehushtan
- Member
- Registered: 2013-03-09
- Posts: 957
Re: Find the equations
If the equation of the tangent line is y = mx + c we have
So we want to find distinct points x=a and x=b such that
Let u = a + b and v = ab; then [3] and [4] can be expressed as
Substituting into [6]
But
We reject this since a and b must be distinct.
Hence
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#7 2016-01-02 17:25:55
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