Quadratic expressions Flashcards
(11 cards)
The 2 signal for Quads…
An expression with a squared variable
Set up for a squared product like (x-3)(x+4)
Roots are what? and how many exist
Roots are the solutions to a quad, typically there are two but sometimes only 1 exists
How to distribute two expressions…
use FOIL, every term gets multiplied following this order
Opposite of distributing is… and how do I solve?
factoring. Consider relationship of coefficient on the variable term and the constant at the end.
- The coefficient is the SUM of the factored pair
- The constant is the product of the same pair
Zero product rule? and why it matters
Set quad to zero before proceeding… you can then find out the potential roots for a variable
If every term in expression is multiplied by a common number or the squared term is negative… what can I do?
Factor out that number. If the squared term is negative simply factor out -1
Never create ___ when dividing a number off the squared term.
a Fraction term!
A quad with NO coefficient term.
Exp X^2 - 9
Take square roots of the constant and record both negative/positive possibilities.
Watch out: if the result under the square root is negative, the solution is imaginary
A quad with NO constant
X^2 - 2x
Simply factor out the variable
X (x - 2)
Quads with higher powers can be solved by? Also what does the largest power tell you??
X^3 - 3x^2 + 2x
Factor X to the front! The largest power reveals the number of roots, if problem said X does not equal 0, you can ignore
X (x^2 - 3x +2)
How to approach quads in fractions??
Same process except first you must cancel out common factors…
Can multiply each term by an LCM
OR
factor out a term in the numerator and then cancel out with denominator