# Mat 117 Week 8 Quiz

Topics: Quadratic equation, Length, Orders of magnitude Pages: 3 (731 words) Published: July 15, 2012
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Date ______________________

MAT117
Quiz 4 - Applications
Chapter 11
10 problems – 5 points each
50 points possible

Solve all problems and attach your solutions document in your Assignment Section Remember to use Equation Editor or MathType when appropriate. Remember to check your steps carefully. Please use the rightmost column to show your steps.

CorrectSolution?| Appropriate Steps Shown?| Credit Earned per Problem| Y| Y| Full Credit|
Y| N| Partial Credit|
N| Y| Partial Credit|
N| N| No Credit|

Grading(Please Leave Blank)| | Concepts and Skills:Show all steps when appropriate.| | 1.| If you are looking at a graph of a quadratic equation, how do you determine where the solutions are?The solutions of the graph of a quadratic equation are the x-coordinates of the points where the graph crosses or touches the x-axis.| | 2.| * a) Without graphing, how do you know if a parabola opens upward or downward? Give an example. y=ax2+bx+c If "a" is positive, opens upward.

If "a" is negative, opens downward. * * b) Without graphing, how do you determine the vertex of a parabola? Give an example.Use the equation -b over 2a and this will give you x. Now you plug in your answer and you have your vertex * * * | | 3.| Solve by completing the square: Solutions: x=7, x=-1| | 4.| Solve by using the quadratic formula:(x-9)(x+5)=0

x-9=0x=9
x+5=0
x=-5|
| 5.| Solve by factoring: Solutions x=-3,-1|
| | Applications: Be sure to show the equations or inequalities using variables.| | 6.| The length of a rectangle is 1 cm more than 4 times its width. If the area of the rectangle is 97 cm2, find the dimensions of the rectangle to the nearest thousandth.Let x be the width.

Let 4x + 1 be the length.

=> x(4x+1) = 97 cm²

=> 4x² + x - 97 = 0

=> x² + x/4 - 97/4 = 0

=> ( x +...