| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.92 |
| Score | 0% | 58% |
A cylinder with a radius (r) and a height (h) has a surface area of:
4π r2 |
|
π r2h |
|
π r2h2 |
|
2(π r2) + 2π rh |
A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The volume of a cylinder is π r2h and the surface area is 2(π r2) + 2π rh.
Solve for b:
b2 - 10b - 17 = -3b + 1
| 9 or -8 | |
| -3 or -8 | |
| -2 or 9 | |
| -5 or -8 |
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:
b2 - 10b - 17 = -3b + 1
b2 - 10b - 17 - 1 = -3b
b2 - 10b + 3b - 18 = 0
b2 - 7b - 18 = 0
Next, factor the quadratic equation:
b2 - 7b - 18 = 0
(b + 2)(b - 9) = 0
For this expression to be true, the left side of the expression must equal zero. Therefore, either (b + 2) or (b - 9) must equal zero:
If (b + 2) = 0, b must equal -2
If (b - 9) = 0, b must equal 9
So the solution is that b = -2 or 9
Factor y2 - 13y + 40
| (y + 8)(y - 5) | |
| (y - 8)(y - 5) | |
| (y + 8)(y + 5) | |
| (y - 8)(y + 5) |
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 40 as well and sum (Inside, Outside) to equal -13. For this problem, those two numbers are -8 and -5. Then, plug these into a set of binomials using the square root of the First variable (y2):
y2 - 13y + 40
y2 + (-8 - 5)y + (-8 x -5)
(y - 8)(y - 5)
The formula for the area of a circle is which of the following?
a = π r |
|
a = π d2 |
|
a = π r2 |
|
a = π d |
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.
The dimensions of this cylinder are height (h) = 8 and radius (r) = 6. What is the volume?
| 405π | |
| 288π | |
| 243π | |
| 36π |
The volume of a cylinder is πr2h:
v = πr2h
v = π(62 x 8)
v = 288π