1. The problem statement, all variables and given/known data Recently got a ti-89 and when I use it to derive for example d(x^2+4x-10, x) I get a decimal, 5.27 instead of getting 2x+4. 3. The attempt at a solution I tried changing the mode to exact, approx, and auto. All give the same answer. I tried pressing the diamond button before ENTER, only in the exact mode it gave me a fraction.