A <u>helix</u> is a curve for which the tangent makes a constant angle with a fixed line. The shortest path between two points on a cylinder (one not directly above the other) is a fractional turn of a helix, as can be seen by cutting the cylinder along one of its sides, flattening it out, and noting that a straight line connecting the points becomes helical upon re-wrapping (see attached diagram for helix).

The parametrization for the helix is

$\left\{\begin{array}{l}x=r\cos t\\ \\ y=r\sin t\\ \\z=at\end{array}\right.,$

where $r$ is the radius of the helix, $a$ is the constant, and $t\in [0,2\pi )$ is the parameter

7 0

3 years ago

During a four-week period, you worked the following hours: Week 1- 363 /8 hr; Week 2- 411 /4 hr; Week 3- 401 /2 hr; Week 4- 383

Dafna11 [192]

The average number of hours can be calculated using the following rule:
average number of hours = total number of hours / total number of weeks

total number of hours = 36 3/8 + 41 1/4 + 40 1/2 + 38 3/8 = 313/2 hours
total number of weeks = 4 weeks

Average number of hours per week = (313/2) / (4) = 39 1/8 hour

Based on the above calculations, the correct answer is:
C. 39 1/8 hour

4 0

3 years ago