Question

1. The number of computers infected by a virus t minutes after it first appears usually increases exponentially. In 2000, “Love Bug” virus spread from 100 computers to about 1,000,000 computers in 2 hours (120 minutes).

a) Find the growth rate k.

b) Give the differential equation for the number P(t) of computers infected after t minutes.

c) How fast was the virus spreading when 1,000,000 computers were infected?

2. Find the slope of the tangent line to the graph of ?=???/?^2 at the point x=1. (y= lnx over x squared)

3. An investment of $5,000 earns 6% interest compounded continuously.

a) Give the exponential growth function for the amount A(t) in the account after t years.

b) How long will it take the investment to triple?

Answer 1