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rsfjr87
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HP Prime expression manipulation

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Hello all,

I am having some issues with expression manipulation in the CAS mode.

Fw. Ver. 13441

For example, I enter the expression

1/x = 1 + 1/a

How can I isolate the variables? In order to get either a= x/(x-1) or x = a/(a+1)?

I tried using solve(), but, sometimes the CAS returns something inconsistent. Is there a better way?

All the best

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Jan_D
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Hi,

 

i think using solve() is the way to do it.

 

Suppose that you want to isolate x and expect the symbolic answer x=a/(a+1)

 

In that case it would be necessary that the variable a has no content stored into it, and to assure this you would have to delete its content if necessary.

 

You could do this with the help of the Memory Manager, with the help of the Vars key or by using:

 

purge(a)

 

In general, to avoid problems, it can be a good idea to use:

 

purge (a,x)

 

which converts both a and x  to abstract variables with no content.

 

Also replacing eventual decimal numbers in your equation by the exact ones, eg replacing 23.4 by 234/10 can be a good idea.

 

One of the ways to do this is using the exact command.

Example:

exact(1/x=23.7+1/a)

 

 

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