| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.22 |
| Score | 0% | 64% |
If the area of this square is 9, what is the length of one of the diagonals?
| 8\( \sqrt{2} \) | |
| 7\( \sqrt{2} \) | |
| 3\( \sqrt{2} \) | |
| 5\( \sqrt{2} \) |
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 = \( \sqrt{a} \) = \( \sqrt{9} \) = 3
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 = 32 + 32
c2 = 18
c = \( \sqrt{18} \) = \( \sqrt{9 x 2} \) = \( \sqrt{9} \) \( \sqrt{2} \)
c = 3\( \sqrt{2} \)
Factor y2 - 64
| (y - 8)(y + 8) | |
| (y + 8)(y - 8) | |
| (y + 8)(y + 8) | |
| (y - 8)(y - 8) |
To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -64 as well and sum (Inside, Outside) to equal 0. For this problem, those two numbers are -8 and 8. Then, plug these into a set of binomials using the square root of the First variable (y2):
y2 - 64
y2 + (-8 + 8)y + (-8 x 8)
(y - 8)(y + 8)
If BD = 11 and AD = 13, AB = ?
| 2 | |
| 14 | |
| 16 | |
| 3 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDThe dimensions of this cube are height (h) = 9, length (l) = 8, and width (w) = 8. What is the volume?
| 180 | |
| 576 | |
| 126 | |
| 189 |
The volume of a cube is height x length x width:
v = h x l x w
v = 9 x 8 x 8
v = 576
The endpoints of this line segment are at (-2, -8) and (2, 0). What is the slope-intercept equation for this line?
| y = 3x - 4 | |
| y = \(\frac{1}{2}\)x + 1 | |
| y = x - 1 | |
| y = 2x - 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, -8) and (2, 0) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(0.0) - (-8.0)}{(2) - (-2)} \) = \( \frac{8}{4} \)Plugging these values into the slope-intercept equation:
y = 2x - 4