Algebra Flashcards
Term
A term is a numerical constant or the product (or quotient) of a numerical constant and one or more variables
Variable
A letter used to represent a quantity whose value is unknown
Expression
An algebraic expression is a combinatiin of one or more terms.
Terms in an expression are separated by either addition or subtraction signs
Coefficient
In the term 3xy, 3 is called a coefficient.
In a single term, such as z, 1 is the coefficient
Constant
A value that does not change
Monomial
A single term
Polynomial
Expression with more than one term
Binomial
A polynomial with exactly two terms
Trinomial
A polynomial with exactly three terms
(a + b)^2
a^2 + 2ab + b^2
(a - b)^3
a^3 - 3a^2b + 3ab^2 - b^3
a^2 - b^2
(a + b)(a - b)
Quadratic formula
ax^2 + bx + c = 0
x = (-b +- sqrt(b^2 - 4ac))/2a
if the expression under the square root is 0, then there is only one solution, if negative there is no (real number) solution.
Domain of a function
the set of all permissible inputs
A mixture of 12 ounces of vinegar and oil is 40% vinegar. How many ounces of oil must be added to produce a mixture that is only 25%?
x = number of ounces of oil to be added
new mixture = 12 + x ounces
ounces of vinegar = 0.4 * 12 = 4.8
new mixture must be 25% vinegar, so:
amount vinegar / amount new mixture = 0.25
4.8 / (12 + x) = 0.25
4.8 = 3 + 0.25x
x = 1.8/0.25 = 7.2
Jeff and Dennis drove the same course at average speeds of 51mph and 54mph, respectively. It took Jeff 40 minutes to drive the course, how long did it take Dennis?
The distance d is equal to the rate r, in mph, and the time t, in hours: d = rt
51*(40/60) = 54*(x/60) 51*40 = 54x
Radio costs $30 to make. 500 radios are produced and sold. What must be the selling price per radio to ensure that the profit (revenue from sales minus production cost) is greater than $8200?
y is revenue from sales
500( y - 30) > 8200
y > 46.4
Quadrants
Counterclockwise I, II, III, IV
Reflection of a graph about the line y = x
Interchange the x and y in the equation of any graph.
y = 2x + 5 reflected about the line x = y x = 2y + 5 => y = (1/2)x - (5/2)
x-intercepts of a parabola
The solutions of the equations are the x-intercepts.
The y-intercept is the equation when x=0.
Equation of a circle
A circle with a center point (a,b) and radius r.
(x - a)^2 + (x - b)^2 = r^2
For any function h(x) and any positive number c:
h(x) + c
h(x) shifted UP c units
For any function h(x) and any positive number c:
h(x) - c
h(x) shifted DOWN c units
For any function h(x) and any positive number c:
h(x + c)
h(x) shifted to the LEFT c units
For any function h(x) and any positive number c:
h(x - c)
h(x) shifted to the RIGHT c units
For any function h(x) and any positive number c:
c*h(x)
h(x) stretched vertically by a factor of c if c > 1.
h(x) shrunk vertically by a factor of c if 0 < c < 1.