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FS_101342551-Visitor
1-Visitor
September 26, 2023
Solved

Getting "Bad solve variable." when trying to solve simple implicit derivative using Mathcad Prime 9

I'm trying so solve an implicit differentiation example but I keep getting bad solve variable error

 

This is my example:

x^2+y^2=25

 

2023-09-25 21_03_01-PTC Mathcad Prime 9.0.0.0 - Untitled.png

 

 

Werner_E
Werner_EAnswer
25-Diamond I
September 26, 2023

Could it be that you are either looking for this

Werner_E_2-1695726185594.png

 

or this

Werner_E_3-1695726199909.png

or are you really looking for an explicit expression for y'(x)

Werner_E_4-1695726357335.png

 

The 'simplify' modifier isn't necessary in case of this expression and was just used out of habit.
And of course you also can omit the "-25" because the derivative of a constant is zero anyway.

 

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4 replies

terryhendicott21-Topaz II
21-Topaz II
September 26, 2023

Hi,

Capture.JPG

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FS_101342551-VisitorAuthor
1-Visitor
September 26, 2023

Hi,

 

I used it as an example to be able to do implicit differentiation for a simple equation. I was able to get the answer you got but I would like to solve for y' or dy/dx. I have a more complicated equation that I need to differentiate. 

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Werner_E
Werner_E25-Diamond IAnswer
25-Diamond I
September 26, 2023

Could it be that you are either looking for this

Werner_E_2-1695726185594.png

 

or this

Werner_E_3-1695726199909.png

or are you really looking for an explicit expression for y'(x)

Werner_E_4-1695726357335.png

 

The 'simplify' modifier isn't necessary in case of this expression and was just used out of habit.
And of course you also can omit the "-25" because the derivative of a constant is zero anyway.

 

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FS_101342551-VisitorAuthor
1-Visitor
September 26, 2023

The third option is what I was looking for. Thanks!

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