| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.80 |
| Score | 0% | 56% |
A coordinate grid is composed of which of the following?
all of these |
|
x-axis |
|
origin |
|
y-axis |
The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.
Which of the following is not required to define the slope-intercept equation for a line?
y-intercept |
|
x-intercept |
|
slope |
|
\({\Delta y \over \Delta x}\) |
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.
The endpoints of this line segment are at (-2, -3) and (2, 7). What is the slope-intercept equation for this line?
| y = 3x + 3 | |
| y = 2\(\frac{1}{2}\)x + 2 | |
| y = 2\(\frac{1}{2}\)x - 4 | |
| y = 3x + 0 |
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 2. 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, -3) and (2, 7) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(7.0) - (-3.0)}{(2) - (-2)} \) = \( \frac{10}{4} \)Plugging these values into the slope-intercept equation:
y = 2\(\frac{1}{2}\)x + 2
If the base of this triangle is 1 and the height is 6, what is the area?
| 3 | |
| 54 | |
| 63 | |
| 32 |
The area of a triangle is equal to ½ base x height:
a = ½bh
a = ½ x 1 x 6 = \( \frac{6}{2} \) = 3
The dimensions of this cylinder are height (h) = 3 and radius (r) = 7. What is the surface area?
| 14π | |
| 18π | |
| 130π | |
| 140π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(72) + 2π(7 x 3)
sa = 2π(49) + 2π(21)
sa = (2 x 49)π + (2 x 21)π
sa = 98π + 42π
sa = 140π