Can anyone help me to solve this problem,

[ptc-6561582]

Hi all,

I tried to use two equations to solve two unknowns, but it said cannot find answer because needing at least two arguments that is applied to 1.

I don't understand what that means. I have attached the worksheet and looking forward to hearing your solutions.

thanks

[Fred_Kohlhepp]

The function In() requires two arguments, you supplied one (A/D). Change to In(A,D), and your sheet calculates.

[ptc-6561582]

Many thanks for your replying, I tired to change to In(A,D) like you said it did calculate.

But it seems the answer calculated is slightly different due to In(A/D) and In(A,D) have a different meaning.

What do you think?

[Fred_Kohlhepp · Accepted solution]

Your sheet was using the function In() function, not ln(). Mathcad won't evaluate In(A/D), that function requires two inputs.

[ptc-6561582]

Appreciate your help, I saw I typed the wrong capital. Again, Many thanks

[RichardJ]

You had the modified second order Bessel function, not the natural log.

Please don't post the same question twice. I just answered on the other thread, only to find Fred had already answered on this one.