Exercise 10.1
1. Taking for granted that et is its own derivative, use the chain rule to find dy/dt for the following:
(a) y = 4e3t
Exercise 10.2
1. What is the instantaneous rate of growth of y in each of the following?
a) y = e0.07t (b) y = 15e0.03t (c) = Ae0.4t (d) y = 0.03et
Exercise 10.3
1. What are the values of the following logarithms?
(a) log10 0.0001
2. Evaluate the following:
(a) loge e-4 (b) loge(1/e2) (c) lnex - elnx
Exercise 10.5
1. Find the derivatives of:
(a) y = e1 - 9t (b) y = 5e2- t2 (c) y = xex (d) y = x2e2x (e) y = axebx +c
2. Find the derivatives of:
(a) y = ln (atc) (b) y = 5 ln(t +1)2 (c) y = ln [x(1 - x)8] (d) y = ln(2x/(1+x)) (h) y = 5x4 In x2 7t
3. Find the derivatives of the following by first taking the natural log of both side
(a) y = (x2 + 3)ex2+1
Exercise 12.2
1. Use the Lagrange-multiplier method to find the stationary values of z:
(a) z = X(Y + 4), subject to x + y = 8.
(b) z = 7 - y+ x2, subject to x + y = 0.
2. Write the Lagrangian function and the first-order condition for stationary values (without solving the equations) for each of the following:
(a) z= x + 2y+ 3w + xy- yw, subject to x + y+ 2w = 10.
(b) z = x2 + 2xy+ yw2, subject to 2x + y + w2 = 24 and x + w = 8.