# Sec-43 - Math 1300 Section 4.3 Notes Factoring Polynomials...

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

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:

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 5

Sec-43 - Math 1300 Section 4.3 Notes Factoring Polynomials...

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

View Full Document
Ask a homework question - tutors are online