Sec-43 - Math 1300 Section 4.3 Notes Factoring Polynomials Some trinomials that can be factored do not look like the special trinomials from the

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Math 1300 Section 4.3 Notes 1 Factoring Polynomials Some trinomials that can be factored do not look like the special trinomials from the previous sections. Factor trinomials, written ax 2 + bx + c , by doing the following rules: 1. Factor out the GCF of all three terms. Use the resulting trinomial for the rest of the steps. If a is negative, also factor out –1 along with the GCF. 2. Check that the square root of b 2 – 4 ac is a whole number. If b 2 – 4 ac is negative, then we cannot factor the trinomial. If the square root of b 2 – 4 ac is not a whole number, then the factored form of ax 2 + bx + c will have fractions or square root signs in it. We will not be factoring these in this section. 3. Look at the sign of the constant term. a. If the second sign (the one before the constant term) is a + sign, then both signs in the factored form are whatever the first sign is. ax 2 + bx + c = ( __ + __ )( __ + __ ) or ax 2 bx + c = ( __ – __ )( __ – __ ) b. If the second sign is a – sign, then the signs in the factored form are different. ax 2 + bx c = ( __ + __ )( __ – __ ) or ax 2 + bx c = ( __ + __ )( __ – __ ) 4. Find two numbers that multiply together to give ac but add up to give b . Keep the signs of a , b , and c with the numbers. 5. Rewrite in preliminary factored form: a. Write the GCF on the outside of the factored form. b. In both sets of the parentheses, write ax c. Write the appropriate signs from step 3. d. Write the two numbers found in step 4, one in each set of parentheses. 6. Factor out any GCFs from the sets of parentheses and throw them away. 7. Rewrite. This is the final factored form. Examples: 1. Factor 3 x 2 + 5 x + 4. Step 1: Find GCF(3 x 2 , 5 x , 4). The GCF is 1 since none of the coefficients have a factor in common. Step 2:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/22/2012 for the course MATH 1300 taught by Professor Staff during the Spring '08 term at University of Houston.

Page1 / 5

Sec-43 - Math 1300 Section 4.3 Notes Factoring Polynomials Some trinomials that can be factored do not look like the special trinomials from the

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online