| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
The formula for volume of a cube in terms of height (h), length (l), and width (w) is which of the following?
h x l x w |
|
lw x wh + lh |
|
h2 x l2 x w2 |
|
2lw x 2wh + 2lh |
A cube is a rectangular solid box with a height (h), length (l), and width (w). The volume is h x l x w and the surface area is 2lw x 2wh + 2lh.
If side a = 2, side b = 2, what is the length of the hypotenuse of this right triangle?
| \( \sqrt{20} \) | |
| \( \sqrt{41} \) | |
| \( \sqrt{10} \) | |
| \( \sqrt{8} \) |
According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:
c2 = a2 + b2
c2 = 22 + 22
c2 = 4 + 4
c2 = 8
c = \( \sqrt{8} \)
If the area of this square is 25, what is the length of one of the diagonals?
| 4\( \sqrt{2} \) | |
| 3\( \sqrt{2} \) | |
| 5\( \sqrt{2} \) | |
| 8\( \sqrt{2} \) |
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 = \( \sqrt{a} \) = \( \sqrt{25} \) = 5
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 = 52 + 52
c2 = 50
c = \( \sqrt{50} \) = \( \sqrt{25 x 2} \) = \( \sqrt{25} \) \( \sqrt{2} \)
c = 5\( \sqrt{2} \)
If AD = 13 and BD = 11, AB = ?
| 7 | |
| 3 | |
| 2 | |
| 9 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDSolve for z:
z2 - 11z + 5 = -5z - 3
| 3 or 1 | |
| 6 or -3 | |
| 2 or 4 | |
| -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:
z2 - 11z + 5 = -5z - 3
z2 - 11z + 5 + 3 = -5z
z2 - 11z + 5z + 8 = 0
z2 - 6z + 8 = 0
Next, factor the quadratic equation:
z2 - 6z + 8 = 0
(z - 2)(z - 4) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (z - 2) or (z - 4) must equal zero:
If (z - 2) = 0, z must equal 2
If (z - 4) = 0, z must equal 4
So the solution is that z = 2 or 4