back to unit2  from a graph  using ti84
x intercepts(or zeroes) from an equation:
Replace the y variable with a zero, then solve for x. The x values that are the solutions are the x intercepts. The x intercepts are also called zeroes when the function is a polynomial.
Quadratic Example(vertex form)

Rational Example 


Quadratic Example(factored form) 

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x intercepts on the ti84
put the equation on the calculator using the y= button
Find the CALC word and use the 2ND key to access it. Then from the menu select zeroes. The calculator calls x intercepts zeroes.
>Use the arrrow keys to mark the side of the graphed function that is on the left side of the zero and hit ENTER , then mark the graphed function on the right side of the zero and hit ENTER. When the calculator says Guess? hit Enter again. The coordinates of the x intercept will be written on the bottom of the screen.