| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.79 |
| Score | 0% | 56% |
Which of the following is not required to define the slope-intercept equation for a line?
\({\Delta y \over \Delta x}\) |
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y-intercept |
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slope |
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x-intercept |
A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.
Which types of triangles will always have at least two sides of equal length?
isosceles and right |
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equilateral, isosceles and right |
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equilateral and right |
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equilateral and isosceles |
An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.
If a = c = 9, b = d = 8, and the blue angle = 63°, what is the area of this parallelogram?
| 24 | |
| 6 | |
| 9 | |
| 72 |
The area of a parallelogram is equal to its length x width:
a = l x w
a = a x b
a = 9 x 8
a = 72
The endpoints of this line segment are at (-2, -2) and (2, 8). What is the slope-intercept equation for this line?
| y = 2\(\frac{1}{2}\)x - 4 | |
| y = -2\(\frac{1}{2}\)x + 0 | |
| y = 2\(\frac{1}{2}\)x + 3 | |
| y = 1\(\frac{1}{2}\)x + 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 3. 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, -2) and (2, 8) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(8.0) - (-2.0)}{(2) - (-2)} \) = \( \frac{10}{4} \)Plugging these values into the slope-intercept equation:
y = 2\(\frac{1}{2}\)x + 3
The formula for the area of a circle is which of the following?
a = π d2 |
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a = π r |
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a = π r2 |
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a = π d |
The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)2 : a = π r2.