I don't know why mathcad can't solve

[jlee-2]

I practiced integration. First picture is a example that I practiced

After practicing, I applied to my work with same method.

But I got error. I thought why error is generated althogh the method is same. I can't know.

[MikeArmstrong]

The first error I noticed was that you have typed f(r), instead of t(r).

[jlee-2]

I did again as changed f(r) to t(r). But I got error agian...

And it is right to type f(r).

you can know it thorugh first picture

[Werner_E]

Mike Armstrong wrote:

The first error I noticed was that you have typed f(r), instead of t(r).

No, thats not an error! f is just the formal parameter of his function T and can be named whatever he likes. When he calls his function he correctly used function name t as argument, so thats OK.

The reason the definite integral cannot be calculated is that the function is not continuous over the whole range - look at the plot. I have not looked too closely how this function is defined and why its not defined for a range of values because the sheet is too messy and confusing for me. But I guess the reason is the definition of function c() which will not return values for arguments between 5 and 6.5.

We have no problem with

Here is a plot of the function t

[jlee-2]

you are right. the reason that error is generated is due to c(r)

So I correct c(r) and then I get value.

very thank you much. If you don't help me, I can't know the reason.

Thank you very much.

[Werner_E]

Visual check by making a plot of the graph of a function often is a good idea.

[MikeArmstrong]

Werner Exinger wrote:

Visual check by making a plot of the graph of a function often is a good idea.

Great tip Werner

[MikeArmstrong]

Werner Exinger wrote:

Mike Armstrong wrote:

The first error I noticed was that you have typed f(r), instead of t(r).

No, thats not an error! f is just the formal parameter of his function T and can be named whatever he likes. When he calls his function he correctly used function name t as argument, so thats OK

No you are right, but a little pointless in this instance.

[Werner_E]

Mike Armstrong wrote:

Werner Exinger wrote:

Mike Armstrong wrote:

The first error I noticed was that you have typed f(r), instead of t(r).

No, thats not an error! f is just the formal parameter of his function T and can be named whatever he likes. When he calls his function he correctly used function name t as argument, so thats OK

No you are right, but a little pointless in this instance.

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???

[MikeArmstrong]

I meant it was a little pointless passing f(r) as formal parameter of his function T in this instance as he was integrating T with set parameters.

[Werner_E]

After all so far we had seen there was no reason to define T() anyway. But of course this may only be the beginning and if T() is used more often throughout this sheet it would make sense.

[MikeArmstrong]

Fair point.