MAT-261: Pre-Calculus
MAT 261
Section 1.2 – Visualizing & Graphing Data
Cartesian Coordinate System
Ordered pairs= (x, y)
Domain: set of all possible input values
Range: set of all possible output values
Pythagorean Theorem
log²+log²=hypotenuse²
Distance Formula
d= √ ( ( x2−x1)
2
+( y2−y1)
2
Circles
The set of all points in a plane are an equal distance from the center point
That distance is the radius (r)
When centered at (0,0) use: x²+y²=r²
When centered at (h,k) use: (xh)²+(yk)²=r²
o Square root of a negative
When finding the range:
o Use a graph!
Section 1.4: Types of Functions & Their Rates of Change
Slope
Slope represents the average rate of change of y with respect to x
M= rise/run
Intercepts
The x intercept (horizontal intercept) is the point where the graph crosses the xaxis
The y intercept (vertical intercept) is the point where the graph crosses the yaxis
Slopeintercept form is y=mx+b
M is slope
(0, b) is yintercept
Difference Quotients
Average rate of change (similar to slope of a line)
f ( x+h )− f (x )
h
Section 2.1: Equations of Lines
Two equations for a line
o Slope intercept form: y=mx+b
o Point slope form: y−y1=m(x−x1
)
o M is slope in both equation
WEEK 2:
Section 3.1: Quadratic Functions & Models
The simplest quadratic function
o F(x)=x²
o Vertex at (0,0)
o Symmetry at x=0
o Decreasing on (-∞,0)
o Increasing on (0, ∞)
Vertex form of a quadratic
o F(x)= a (x-h) ²+k
o Vertex at (h, k)
o If a>0, the vertex is the minimum
o If a<0, the vertex is the maximum
o Compare to expanded form f(x)= ax²+bx+c
Domain and Range
o Domain is the all the x values that work
Domain of any quadratic is (-∞, ∞)
o Range is all the y values that the function hits
If a>0, start at the vertex and go up forever.
If a<0, start down at -∞ and go up to the vertex
Section 3.2: Quadratic Equations & Problem Solving
The Zero Product Property
o If a × b =0, then a=0, b=0, or both
A second degree or quadratic equation is an equation that can be written in
the form ax²+bx+c, where a, b, and c are real numbers and a is not zero.
Y-intercept (vertical intercept)
o Crosses the y-axis at (0, c)
X-intercepts (horizontal intercept)
o For any function solve f(x)=0
o For a quadratic function
Factor
Complete the square
Use the quadratic formula
The Discriminant
o b²-4ac
o Determines number and type of solutions
Section 3.3: Complex Numbers
Imaginary i
o √-1= i
o i² = -1
o The standard form for an imaginary number is z=a+bi
o To add or subtract imaginary numbers, you combine like term
MAT-261: Pre-Calculus
week 3
Section 4.2: Polynomials Functions and Models
Names of polynomial functions
o Degree 2
o Degree 3
o Degree 4
Number of turning points
o The number of turning points of the graph of a polynomial function of
degree n ≥ 1 is at most n-1
o If a polynomial has t > 0 turning points, its degree must be at least t+1
End Behavior
o Highest degree term “wins” for large x and negative x
Zeros of a function
o For real numbers, these are all the same:
X-intercepts of a graph
Zeros of a function
Roots of a polynomial function
Solutions of p(x)= 0
o If the solution/roots/zeros have a nonzero, imaginary part, there are no
x-intercepts
Even and Odd Functions
o Even function: f(-x) = f(x)
Symmetric about the y-axis
If (x, y) is on the graph, then (-x, y) is too
o Odd function: f(-x) = -f(x)
Symmetric about the origin
If (x, y) is on the graph, then (-x,-y) is too
o Even functions
Polynomials with only even powers
Cos(x)
Sec(x)
o Odd functions
Polynomial with only odd powers
Sin(x)
Tan(x)
Csc(x)
Cot(x)
o Both even and odd f(x)=0
High and Low points
o Extremum: maximum or minimum
o Extrema: minima or maxima
o Local or relative extrema
Highest or lowest point in the neighborhood
Occurs at the turning point of polynomials
o Absolute maximum
week 4: quiz