Exam prep Flashcards
A relation is a function if:
It pass the two test:
VLT or for every x- coordinate their is only one y-coordinate
What is domain?
Values of all the x- coordinate
What is range?
Values of all the y- coordinate
How can you tell apart a linear, quadratic, and exponential?
linear: first difference are the same
quadratic: second difference are the same
exponential: difference aren’t the same ex. 2 with a little x.
What is function notation?
It’s substituting f of x, and then solving
In y = a ( x-h)2 +k
what is “a”
If a is positive: open up
if a is negative it open down, and reflects into the x- axis
if a is a whole number it has a vertical stretch (narrower)
if it a faction or decimal it a compression ( wider)
In y= a (x-h)2 + k
what is h
if h is positive: shifts right
if h is negative: shifts left
In y= a (x-h)2 + k
what is k
if k is positive it shifts up
if k is negative it shifts down
what is the mother of all parabolas?
y=x2
How do you foil?
first, outside, inside, last
( x + 4) (2x-9)
how do you common factor?
Find the GCF
dived all number by
the GCF goes outside the bracket, and the dived number go inside.
how do you do simple trinomials
find the GCF
then do the chart method find the two numbers that multiply by a and c, but add to b
then put those number in the bracket
How do you know if it’s simple or complex trinomials?
simple their GCF is the first number “a”
complex find another GCF or do the chart method
in y= a (x-r) (x-s)
what is a
if a is positive the graph open up if it’s negative it open down
if a is > 1 it stretches’
if 0< a> a it compressed
in y= a( x-r) (x-s)
what is r and s?
r and s are the zeros
how do you find the zeros in an equation from standard from?
fully factor
then replace y for 0
and you switch the sign of the number
how do you find the difference of the square?
common factor if need be
you square root each factor
then plug it in
(x-6) (x+6)
how do you find the perfect square?
keep the sign
square root the a and c term
and plug it in with a exponent
(x-4)2 check it by multiply 2(4) (x) = the b term
what is the optimal value
is the value of the y- co-ordinate of the vertex
what is the axis of symmetry
divides the the parabola into two equal halfs
what the discriminant
b2 - 4 a c
how many roots are their if the discriminant is positive, negative or equal
positive= 2
negative= 0
equal= 1
how do you use the discriminant to find the roots?
plug into your equation
when do you use the whole discriminant formula?
when your looking for zeros, and the number are tricky like decimal
In application of quadratics how do you find the height?
you plug in 0 as you x in your equation
and then you solve
In application of quadratics how do you find when something is going to hit the ground?
your looking for the zeros
so factor if needed then plug in zeros and change the signs.
In application of quadratics how do you find the max/ min height?
add your zeros and dived by 2
this get you your x value
the plug that number into your equation
how do you solve by graphing?
this is used for standard form
Use the formula x= -b/ 2(a)
this find you the x of your vertex
then plug that x into your equation to get y of your vertex
then make a t chart, and plug in the x to find your y
graph
find your solution
when creating an equation from graphs
for factor form what do you need?
y= a (x-s) (x-r)
x= inter
y= inter
plug in to solve for “a”
when creating an equation from graphs for vertex form what do you need?
y= a (x-h) 2 +k
vertex
y= inter
plug in to solve for “a”
how do you complete the square?
stander to vertex
remove a from the first two terms
then find b/2 exponent 2
plug in that number as positive and negative
find the square root of a and the positive
now plug those number (x+3) 2 -9
multiply the negative by the outside number
then add by the out out side number to
get you equation.
what can you find with Vertex form?
y= a ( x-h) 2 +k
Vertex: can be found (h,k)
y= inter: plug in 0 to solve
axis: is h
optimal value: k
x- inter: hard to find you have to factor first
what can you find with factored form?
a(x-s) (x-r)
x- inter: switch the sign of s and r
vertex: add the x’s and then dived by 2: (x,?)
then sub to solve for for y of the vertex
y= inter: plug in 0 to slove
axis: x
optimal: y
what can you find with standard form?
ax2 + bx+ c
y= inter: plug in 0 to solve
vertex: must compete the square
x- inter: factor first
axis symmetry/ optimal value: factoring, x= -b/ 2(a)
or complete the square