Please explain:

1. The following function represents the cots in hundreds of dollars for producing pens, where x represents 1000's of units

c(x)=.4x^2-16x+200 , 25 ≤ x ≤ 40

a) Estimate the cost for making the 36th 1000-unit run using the marginal cost function derivative.

b) Find the actual cost for making the 36th 1000-unit run.

c) Find the percent margin of error for your cost estimate in part a.

2. Find the equation of the line tangent to f(x)=1/x at the point x=1