Quadratic parabolas Flashcards
Expand a perfect square
(x+a)(x+a)
do first one squared
then two times the two multiplied together
then the second one squared
x^2 + 2ax + a^2
How to factorize (x+6)(x+2)
x(x+2)+6(x+2)
Factorizing with four terms
group them into pairs with the same expression in the brackets. then use one of the brackets with the two numbers outside
ax^2 +ax+2x+2
ax(x+1)+2(x+1)
(x+1)(ax+2)
Factorizing quadratic trinomials
Find two numbers that when added together equal the coefficient of bx and when multiplied together equal c.
x^2 +7x+6 –> (x+1)(x+6)
Distributive law
a(b+c)=ab+ac
FOIL
First outer inner last
Product of conjugates (a+b)(a-b)
(a+b)(a-b) = a^2-b^2
equation of a verticle line
x= a number
Quadratic function
f(x)=ax^2 + bx + c
a,b,c are fixed numbers
c is the y intercept
x, f(x) are variables
f(x) = y
What is the min/max point of a parabola called
the vertex
how many x intercepts are there on parabola
2
what is the axis of symmetry
the line that goes through vertex
x= a number
How to find x intercepts from a standard form quadratic function
rearrange the function so it is
ax^2 + bx + c = 0
then find the numbers that when added together equal b and when multiplied equal c. the opposite sign of those numbers are the x intercepts
how does c affect parabola
how up/down it is
how does b affect parabolas
how left to right it is
how does a affect parabola
how narrow/wide and if it is concave up or concave down
Vertex in each form
Vertex form = h and k
standard form = (-b/2a), f(-b/2a)
Factored form = expand then use standard form method
axis of symmetry from each form
Vertex form = h
standard form = (-b/2a)
factored form = expand and then use (-b/2a)
how to go from standard to vertex form and vice versa
add a number to complete the square, then subtract it
factor the perfect square and solve the outer two numbers
from vertex to standard expand.
how to go from standard to factored form and vice versa
Put all the terms on the left hand side, factor like a trinomal, or split up ax^2 and examine factors of c, then apply the zero product theorem to find vertex.
how to find the parabola from a function
First, find the vertex, then the x intercepts, and then the y intercept. The graph accordingly.
domain
The numbers included in x points (x = all real numbers)
range
The numbers included in y points
(y > a)
vertical line test
used to determine if the given graph represents a function: if the line intersects at at most one place its a function (no more than one intersection per vertical line)
x intercepts from quadratic functions
vertex form = expand to standard form, then factor it to factored form.
Standard form = factor to factored form
Factored form = (p,0) (q,0)
function
a set of ordered pairs in which the first corresponds to a distinct second coordinate. (no vertical points)