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+--- Thread: Prime vs Nspire (/thread-20465.html)
Prime vs Nspire - G. Cook - 09-06-2023 10:51 PM
I have been trying to algebraically solve an equation of the type (1+(y/365))^365 =(1+x) for y=f(x). The solution is not difficult using pencil & paper only.
My Prime (G2, Version 2.1.14370 (2023 04 13)) when using the CAS "solve" in CAS mode creates an extremely large, complex polynomial not the algebraic reversion of the equation.
I could find no other way to re-order the expression
On the other hand, My TI-Nspire CXII CAS "solve" command immediately outputs
y = 365*(x+1)^(1/365) -365 which is the desired function.
Certainly, the Prime MUST be able to accomplish the same task but the "how" is beyond me.
G.C.
HP: 49g+, 50g, Prime G2
TI: SR50, 86, 89, N-spire
Casio: fx-702p, 9750GIII, CG50
RE: Prime vs Nspire - Nigel (UK) - 09-06-2023 11:09 PM
The HP Prime app on this iPad gives the correct answer at once without any tricks. It might be worth purging x and y before solving, perhaps?
Nigel (UK)
RE: Prime vs Nspire - Albert Chan - 09-06-2023 11:14 PM
solve() default to solve for x, unless specified otherwise. Here, we wanted y
CAS> solve((1+y/365)^365 = (1+x), y)
{ 365*(x+1)^(1/365) - 365 }
RE: Prime vs Nspire - G. Cook - 09-07-2023 04:05 PM
I found the problem. The "complex" box was checked in the CAS settings page. Unchecking the complex box gave the desired results. Thanks for the replies
GC