TI-36X Pro: Stat: x’ and y’ estimates for Exp, Log, Power curves.

[ijabbott]

(12-04-2022 11:45 PM)Matt Agajanian Wrote:  Hi all.

I see that I can calculate x-estimate and y-estimate for linear/ax+b data right from the STAT mode. I don’t see that function when I use other curve models. Or are there x' and y' functions in stat mode for the other regression models? Although the formula can be stored in f(x) and use num-solve to calculate x’ and y’.

Do a and b carry over into register a & b so I can use them in num-solv for solving the equation placed in f(x) for x’ and y’?

a and b do carry over into variables and the regression formula can be saved to f(x) (or alternatively to g(x) on the TI-30X Pro MathPrint).

Yes, you can use num-solv on the f(x) (or g(x)) function saved by the regression calculation to solve x' for f(x')=y' or (g(x')=y'). Alternatively, a and b variables can be used to calculate x' from the inverse function. For example, for ExpReg ab^x, calculate x' = ln(y'/a)/ln(b) directly on the Home screen.

For y', just evaluate the function f(x') (or g(x')).

As you guessed, the x'() and y'() functions on the 2-Var Stats menu assume linear regression.