Graph: y = 2x - 5
y = -2/3x + 3
SEE GRAPH
Solve for x:
100x2 + 36 = D
See answer on board
+/- √(D – 36)/10
Factor: x2 - 17x + 30
(x - 15) (x - 2)
f(x) = 2x2 - 10
g(x) = 7x + 4
Find f(3)
Find g(3)
f(3) = 8
g(3) = 25
What special case quadratic is a4 - b4
Difference of Squares
Find the point of intersection:
y = 2x - 5
y = -2/3x + 3
y = 1
(3, 1)
x = time (days)
y = height (inches)
2 points: (10,6) and (30,18).
Find the equation of the line going through the two points. What is the expected height on day 65?
y = 3/5x
x = 65 y = 3/5x
y = 3/5(65)
Height = 39 inches
Solve: x2 - 17x + 30
x = 15
x = 2
Find the vertex: y = x2 + 10x + 16
(-5, -9)
Factor: a4 - b4
(a2 - b2)(a2 + b2)
OR
(a - b)(a + b)(a2 + b2)
Solve:
1/3x - 2 < -1/3x + 4
x < 9
Cost function: C = (8/3)x + 20
Revenue Function: R = 5x - 1
x = # of days. Graph both functions. When does cost = revenue?
9 days ($44)
(8/3)x + 20 = 5x - 1
Factor and Solve: 2x2 -11x + 15
(2x - 5)(x - 3)
x = 5/2
x = 3
Consider the function x2 + bx - 10, where b is a constant. If the function has an axis of symmetry of x = 7, what's the value of b?
b = -14
Are the following points representative of a function? Why?
(-2,9)
(1,7)
(3,4)
(-2, 11)
What is the equation of a line that goes through the points...
(-2, 11) and (1,2)?
y = -3x + 5
Graph: y = (x-2)2 - 9
SEE GRAPH
Vertex: (2, -9)
X-Intercepts: (-1,0) and (5,0)
Y-Intercept: (0, -5)
What are the sum of the roots of...
2x2 - 11x + 15
x = 5/2
x = 3
5/2 + 3 = 11/2
ANSWER: 11/2 or 5.5
f(x) = 2x2 - 10
g(x) = 7x + 4
For what value, is f(x)>g(x)
a) x = 2
b) x = 3
c) x = 4
d) x = 5
d) x = 5
f(5) = 40
g(5) = 39
At what point do the lines y = 4x - 14 and y = 8x - 26 intersect?
4x - 14 = 8x - 26
x = 3
y = -2
(3, -2)
Graph: 6y - 4x = -24
Find the x and y-intercepts
SEE Graph
y = 2/3x - 4
Y-Intercept: (0,-4)
X-Intercept: (6,0)
A rectangle has an area of 160 m2. The length of the rectangle is 6 meters longer than the width. What is the width? What is the length?
x(x+6) = 160
Width = 10 m
Length = 16 m
Solve by completing the square:
x2 - 4x - 12 = 0
x = 6
x = -2
a) All real numbers
b) All integers
c) All whole numbers
d) All positive real numbers
x = domain = # of video games
Video games CANNOT be negative, CANNOT be a fraction, CAN be zero
ANSWER: c) All whole numbers
a) (x + 3)2 + 4
b) (x + 3)2 - 4
c) (x + 3) (x + 2)
d) (x + 5) (x + 1)
e) (x - 5) (x - 1)
b) (x + 3)2 - 4
AND
d) (x + 5) (x + 1)