Factor: x2 - 3x - 28
(x-7)(x+4)
Solve: x2 - 9x = -18
x = 6, x = 3
x = 13, x = -1
find f(-1) if f(x) =
-(x + 6)2 + 1 when x < -3
-5 when x = -3
2x when -3 < x </= 2
-2
What is the quadratic formula?
x = -b +/- sqrt(b2 - 4ac)/ 2a
Factor: 7x2 - 65x - 50
(7b+5)(b-10)
Solve: 3x2 = -4x + 4
x = 2/3 = 0.667, x = -2
Solve: 4 + |3a| = 10
x = 2, x = -2
Find f(-2) when f(x) =
-x + 3 when x</= -3
-3x - 4 when -3 < x </= 1
-(x - 2)2 + 5 when x > 1
2
What is an extraneous solution?
Values we get when solving equations that aren't really solutions to the equations.
Factor: 7x3 + 71x2 + 72x
x(7x+8)(x+9)
Solve: x2 - 12x + 31 = -4
x = 7, x = 5
Solve: |4x - 8| + 1 = 5x
x = 1
REJECT x = -7
Graph the function:
f(x) = (x + 5)2 + 3 when x < -3
sqrt(x) when x > 0
Quadratic (open dot @ -3)
Square Root graph (open dot @ 0)
How do you find the 'magic number' when completing the square?
(b/2)2
Factor: 4x2 - 20x + 25
(2x-5)2
Solve: x2 - 14x - 49 = 9
x = 7 - sqrt(107), x = 7 + sqrt(107)
Solve: |3x - 1| -1 = 4x
x = -2
REJECT x = 0
Graph f(x) =
-x when -5 </= x < 1
sqrt(x - 1) when x >/= 1
linear graph (closed @ -5, open @ 1)
square root (closed @ 1)
Simplify: CubeRoot(135x6)
3x2 CubeRoot (5)
Factor: 16x2 - 1
(4x + 1)(4x - 1)
Solve: x2 = 5x + 5
x= (5 + 3sqrt(5))/2
x= (5 - 3sqrt(5))/2
Solve: |3x - 3| + 9 = x
NO SOLUTIONS
reject x = -3 and x = 3
Graph f(x) =
x when x < -7
|x| when x > -7
linear (open dot @ -7)
absolute value (open dot @ -7)
When do you know to reject a solution when solving an absolute value equation?
When the solution does not give a balanced equation.