# TI-89 Titanium help

• Calculators
I am trying to graph the function y1=8x*cos(x). But everytime I do an error message tells me that I have an undefined variable. I went to F6 and cleared all variables a-z but i still get this message. Any suggestions?

i2c
Hi, when try factor(2x^2+17xy+y^2) the result is the same equation, the same result with quadratic polynomials doesn't give a facotr answer. Thanks

try this

factor(2x^2+17*x*y+y^2)

xy doesn't mean x*y (it does to you and me but not to the 89)

i2c
When I do a compounding interest problem on my TI-89 Titanium, it returns the answer as a whole number with no decimals. I have tried changing "Exact/Approximate" in the Mode menu, "diamond"-enter, but it always rounds the answer to the next whole number. Any help with this? Thanks.
Change your mode to Float 12

i2c
I am trying to graph the function y1=8x*cos(x). But everytime I do an error message tells me that I have an undefined variable. I went to F6 and cleared all variables a-z but i still get this message. Any suggestions?
1. Make sure you're in Function mode, (i.e. not Polar or Sequence, etc)
2. If that doesn't work, make sure everything you want to keep (like programs/functions, etc) are archived, and press 2nd+On+Left+Right at the same time, it will reset your calculator back to stock, then it should work!

Mark44
Mentor
I am trying to graph the function y1=8x*cos(x). But everytime I do an error message tells me that I have an undefined variable. I went to F6 and cleared all variables a-z but i still get this message. Any suggestions?
1. Make sure you're in Function mode, (i.e. not Polar or Sequence, etc)
2. If that doesn't work, make sure everything you want to keep (like programs/functions, etc) are archived, and press 2nd+On+Left+Right at the same time, it will reset your calculator back to stock, then it should work!
My guess is that the calculator doesn't like 8x, and that the expression on the right should be 8*x*cos(x).

i2c
My guess is that the calculator doesn't like 8x, and that the expression on the right should be 8*x*cos(x).
8x*cos(x) graphs fine for me on my 89.

i am having trouble factoring :(
when i try to factor 4x^3+12x^2-8x i end up getting 4x(x-.561..)(x+3.561..)
i dont know if i have the settings wrong or something

i am having trouble factoring :(
when i try to factor 4x^3+12x^2-8x i end up getting 4x(x-.561..)(x+3.561..)
i dont know if i have the settings wrong or something