Download presentation
Presentation is loading. Please wait.
Published byAlexandra Webb Modified over 9 years ago
1
Finding the Potential Zeros
2
A Theorem that provides a complete list of possible Rational Roots or Zeroes of the Polynomial Equation. A Root or Zero of a function is a number that, when plugged in for the variable, makes the function equal to zero. It states: if P(x) is a polynomial with integer coefficients and if (p/x) is a zero of P(x).
3
P is a a factor of the constant term of P(x) Q is a factor of leading coefficient of P(x) EXAMPLE: P(x)=2x 2 + x 3 – 19x 2 - 9x + 9 P is all factors of 9, which are: +/- 1, +/- 3, +/- 9 Q is all factors of 2, which are +/- 1, +/- 2
4
1. Arrange the forms of the polynomial in descending order by exponent. 2. Write down all factors of constant term. These are all possible values for P. 3. Write down all possible values of leading coefficient. These are all possible values for Q 4. Write down all possible values of P/Q, which equals all possible zeros. 5. Use your calculator to find all real zeroes 6.Use Synthetic or Long division to show which values for (p/q) will be a factor.
5
1. Press [y=] Plug your equation into your Y 1 = 2. Press [2 nd ] [graph] 3. Find any Zeroes under the “Y 1 ” Column 4. Look across to your “X” Column and match up the x that goes with the y=0 5. Which ever number your X is that matches up with your Y=0 is your real Zero.
6
*This is an example from before* P(x)=2x 4 + x 3 – 19x 2 - 9x + 9 first find your P’s and Q’s (which we found before) P = +/- 1, +/- 3, +/- 9 Q= +/- 1, +/- 2 Now divide your P’s from your Q’s. P/Q ** Remember that (p/q) will be both negitive and positive. Simplify each and make sure there are no duplicates **
7
Your P/Q are: +/- 1, +/- ½, +/- 3, +/- 3/2, +/- 9, +/- 9/2 12 possible zeros is your answer! Now use Synthetic or Long division to determine which values for p/q will equal 0.
8
Plug 2x 4 + x 3 – 19x 2 - 9x + 9 into your Y 1 Press [2 nd ] [Graph] Match up your Y 1 =0 to your X Your Real Zeroes are : - 3, - 1, & 3 **Notice how ½ didn’t appear on the calculator that’s why you should always do synthetic or long division and check with your calculator**
10
1. P(x)= x 3 -2x 2 -29x+30 ◦ Find P/Q 2. P(x)= x 4 -x 3 -11x 2 -x-12 ◦ Factor Completely
11
REAL ZEROS: 1. -5,1, & 6 2. -3, & 4
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.