another fsolve question  Printable Version + HP Forums (https://www.hpmuseum.org/forum) + Forum: HP Calculators (and very old HP Computers) (/forum3.html) + Forum: HP Prime (/forum5.html) + Thread: another fsolve question (/thread4194.html) 
another fsolve question  roadrunner  06202015 04:01 PM Can anyone tell me what I am doing wrong? I plotted the function ph2o(X) (code below) and touched Menu/Fcn/Tangent and, as expected, I saw the tangent line at the cursor location that I could trace up and down the curve. [attachment=2185] However, when I plot function tdew(X,15) (code also below) and touch the tangent softkey I get nothing. When I touch slope I get NaN. [attachment=2187] I get the same result with newton, newtonj, and bisection solver. Am I doing something wrong, or is the calculator not capable of that operation on that function? Thanks for reading, Paul Code:
