Question: how to find zeros of a polynomial with a calculator?
Answer: Press Graph. Press More and then Math (F1) Press Lower (F1). Arrow to the left of the x-intercept and press enter. Press Upper (F2). Arrow to the right of the x-intercept and press enter. Press Root (F3). ...  The TI-85 will return a value for x and 0 (or really close to it) for y.