To solve this Arithmetic progression request, which requires a quite simple single line of code calculator I decided to make an universal calculator, which can derive remained parameters automatically from the input data and related formulas.
It's a little bit complicated, but powerful enough to automatically derive the solution form any formulas, containing arithmetic operations: +, -, /, * , ^ and function: sin, arcsin, cos, arccos, tan, arctan, cot, arccot, cosec, arccosec, sec, arcsec, sh, arsh, ch, arch, th, tanh, arth, cth, coth, arcth, sech, arsech, csch, arcsch, exp, ln.
Just enter input data and related formulas in the text field and get solution for remained unknown parameters.
Save the calculation to reuse next time, to extension embed in your website or share share with friends.
The calculator recognizes two special constants - pi = 3.1415926... and e = 2.718....
If something fails to work as you expect it, just let me know in comments.