| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.16 |
| Score | 0% | 63% |
The endpoints of this line segment are at (-2, -3) and (2, -1). What is the slope-intercept equation for this line?
| y = \(\frac{1}{2}\)x - 2 | |
| y = \(\frac{1}{2}\)x + 3 | |
| y = 2x + 3 | |
| y = 2\(\frac{1}{2}\)x - 3 |
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, -1) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-1.0) - (-3.0)}{(2) - (-2)} \) = \( \frac{2}{4} \)Plugging these values into the slope-intercept equation:
y = \(\frac{1}{2}\)x - 2
If the area of this square is 49, what is the length of one of the diagonals?
| \( \sqrt{2} \) | |
| 7\( \sqrt{2} \) | |
| 3\( \sqrt{2} \) | |
| 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 = \( \sqrt{a} \) = \( \sqrt{49} \) = 7
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 = 72 + 72
c2 = 98
c = \( \sqrt{98} \) = \( \sqrt{49 x 2} \) = \( \sqrt{49} \) \( \sqrt{2} \)
c = 7\( \sqrt{2} \)
Breaking apart a quadratic expression into a pair of binomials is called:
normalizing |
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squaring |
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factoring |
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deconstructing |
To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.
What is 5a + 2a?
| a2 | |
| 10a | |
| 3a2 | |
| 7a |
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.
5a + 2a = 7a
The dimensions of this cylinder are height (h) = 5 and radius (r) = 7. What is the surface area?
| 168π | |
| 100π | |
| 120π | |
| 112π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(72) + 2π(7 x 5)
sa = 2π(49) + 2π(35)
sa = (2 x 49)π + (2 x 35)π
sa = 98π + 70π
sa = 168π