1. Jun 22, 2011

### JLindsayLj

1. The Ministry of Health has determined that t day after the detection of a communicable disease, the percent P of a city’s population that will be affected is given by the equation P (t) = 10te^-0.1t 1 ≤ t ≥ 15. How many days after detection will the maximum percent of the population are infected?

2. An air plane starts out travelling 40°E of N (N40°E) at a speed of 850 km/h. It encounters a wind of 120 km/h blowing from the east; find the resultant groundspeed and the direction of the plane.

3. Determine the intersection of the perpendicular line drawn from the point A(-5, 3, 7) to the plane v = (0, 0, 2) + t(-1, 1, 3) + s(2, 0, -3) and determine the distance from point A to the plane.

4. Explain why there is one and only scalar equation of a given plane, whereas there are many different parametric and vector equations for the plane.

5. Discuss the intersection of the three planes given below. Give a geometric interpretation of the system and its solution, and also state whether the system has no solution, a unique solution, or an infinite number of solutions.

4x - 6y + 2z = 10
2x – 3y + z = 0
2x – 18y -8z = 0

2. Jun 22, 2011

### tiny-tim

Welcome to PF!

Hi JLindsayLj! Welcome to PF!

Show us what you've tried, and where you're stuck, and then we'll know how to help!