Originally Posted by
Pete
Thanks Red X, your explanation was good. I did it a bit differently though:
x²(72-4x)
2x (72-4x) + x² (-4)
144x - 8x² - 4x²
144x - 12x²
12x(12-x)
I totally forgot about the product rule for derivatives.
Actually you did it exactly like how I did it
Originally Posted by
sherwood
TI-89 was made specifically to meet the calculator standards that the voyager and 92 wouldn't pass... internally it's the same
Voyager/92 are considered computers because of the qwerty
I think the speed/memory of the calc goes something like:
89 titanium>92+>89-HW2>92>89-HW1>voyager
been a while but I think thats the order
Yeah you could be right, I only chose TI-92+ for the qwerty -- no more catalog searching for functions
Plus i got it on egay for $45