Because K is on the left of the equals sign, Prism recognizes that it is an intermediate variable rather than a variable to be fit by nonlinear regression. Note two comments, one on a line by itself and the other on the same line with equation code. When you enter your equations, you can use any of the functions listed below. Don't use any of those names for your variables. If k is negative, multiply by -1.
Result is in radians.
Result is in radians. Result is in radians. K is in radians. Converts k radians to degrees. If the condition is true, then the result is J. Otherwise the result is k.