| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.89 |
| Score | 0% | 58% |
On this circle, line segment CD is the:
chord |
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diameter |
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circumference |
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radius |
A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).
The dimensions of this cylinder are height (h) = 2 and radius (r) = 9. What is the volume?
| 128π | |
| 16π | |
| 162π | |
| 32π |
The volume of a cylinder is πr2h:
v = πr2h
v = π(92 x 2)
v = 162π
The endpoints of this line segment are at (-2, -7) and (2, -1). What is the slope-intercept equation for this line?
| y = -2x - 3 | |
| y = 3x + 3 | |
| y = 1\(\frac{1}{2}\)x - 4 | |
| y = -3x + 4 |
The slope-intercept equation for a line is y = mx + b where m is the slope and b is the y-intercept of the line. From the graph, you can see that the y-intercept (the y-value from the point where the line crosses the y-axis) is -4. The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, -7) and (2, -1) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-1.0) - (-7.0)}{(2) - (-2)} \) = \( \frac{6}{4} \)Plugging these values into the slope-intercept equation:
y = 1\(\frac{1}{2}\)x - 4
Solve for c:
c2 + 8c + 39 = -4c + 4
| 8 or -2 | |
| -1 or -9 | |
| -2 or -5 | |
| -5 or -7 |
The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:
c2 + 8c + 39 = -4c + 4
c2 + 8c + 39 - 4 = -4c
c2 + 8c + 4c + 35 = 0
c2 + 12c + 35 = 0
Next, factor the quadratic equation:
c2 + 12c + 35 = 0
(c + 5)(c + 7) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 5) or (c + 7) must equal zero:
If (c + 5) = 0, c must equal -5
If (c + 7) = 0, c must equal -7
So the solution is that c = -5 or -7
Which of the following is not a part of PEMDAS, the acronym for math order of operations?
division |
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addition |
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pairs |
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exponents |
When solving an equation with two variables, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)