| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.54 |
| Score | 0% | 71% |
The endpoints of this line segment are at (-2, 0) and (2, -6). What is the slope-intercept equation for this line?
| y = -1\(\frac{1}{2}\)x - 3 | |
| y = 2x + 1 | |
| y = 3x + 3 | |
| y = -1\(\frac{1}{2}\)x - 1 |
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, 0) and (2, -6) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-6.0) - (0.0)}{(2) - (-2)} \) = \( \frac{-6}{4} \)Plugging these values into the slope-intercept equation:
y = -1\(\frac{1}{2}\)x - 3
The formula for the area of a circle is which of the following?
a = π d |
|
a = π r2 |
|
a = π r |
|
a = π d2 |
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.
If the area of this square is 16, what is the length of one of the diagonals?
| 5\( \sqrt{2} \) | |
| 6\( \sqrt{2} \) | |
| \( \sqrt{2} \) | |
| 4\( \sqrt{2} \) |
To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:
a = s2
so the length of one side of the square is:
s = \( \sqrt{a} \) = \( \sqrt{16} \) = 4
The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:
c2 = a2 + b2
c2 = 42 + 42
c2 = 32
c = \( \sqrt{32} \) = \( \sqrt{16 x 2} \) = \( \sqrt{16} \) \( \sqrt{2} \)
c = 4\( \sqrt{2} \)
What is 2a - 3a?
| 6a2 | |
| -1a | |
| a2 | |
| 6a |
To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.
2a - 3a = -1a
If a = 6, b = 9, c = 6, and d = 5, what is the perimeter of this quadrilateral?
| 25 | |
| 26 | |
| 20 | |
| 24 |
Perimeter is equal to the sum of the four sides:
p = a + b + c + d
p = 6 + 9 + 6 + 5
p = 26