Problem 3.9.26
Find the derivative of the following functions.
y = In |x²-1|
Problem 3.9.27
Find the derivative of the following functions.
y = x² (1 - In x²)
Problem 3.9.30
Find the derivative of the following functions.
y = In(cos² x)
Problem 3.9.31
Find the derivative of the following functions.
y = In x / (In x + 1)
Problem 3.9.32
Find the derivative of the following functions.
y = In(e^x + e^-x)
Problem 3.9.63
Calculate the derivative of the following functions. In some cases, it is useful to use the properties of logarithms to simplify the functions before computing f'(x).
y = 4 log₃(x²−1)
Problem 3.9.65
Calculate the derivative of the following functions. In some cases, it is useful to use the properties of logarithms to simplify the functions before computing f'(x).
y = (cos x) In cos²x
Problem 3.9.66
63–74. Derivatives of logarithmic functions Calculate the derivative of the following functions. In some cases, it is useful to use the properties of logarithms to simplify the functions before computing f'(x).
y = log₈ |tan x|
Problem 3.9.69
Calculate the derivative of the following functions. In some cases, it is useful to use the properties of logarithms to simplify the functions before computing f'(x).
f(x) = In(3x + 1)⁴
Problem 3.9.70
Calculate the derivative of the following functions. In some cases, it is useful to use the properties of logarithms to simplify the functions before computing f'(x).
f(x) = In 2x/(x² + 1)³
Problem 3.9.73
Calculate the derivative of the following functions. In some cases, it is useful to use the properties of logarithms to simplify the functions before computing f'(x).
f(x) = In (2x - 1)(x + 2)³ / (1 - 4x)²
Problem 3.9.74
Calculate the derivative of the following functions. In some cases, it is useful to use the properties of logarithms to simplify the functions before computing f'(x).
f(x) = In(sec⁴x tan² x)
Problem 3.9.88
Find the following higher-order derivatives.
d²/dx² (In(x² + 1))
Problem 3.9.95
{Use of Tech} Tangent line Find the equation of the line tangent to y=2^sin x at x=π/2. Graph the function and the tangent line.
Problem 3.9.87.b
Explain why or why not. Determine whether the following statements are true and give an explanation or counterexample.
b. ln(x + 1) + ln(x − 1) = ln(x² − 1), for all x.
Problem 3.9.97c
97–100. Logistic growth Scientists often use the logistic growth function P(t) = P₀K / P₀+(K−P₀)e^−r₀t to model population growth, where P₀ is the initial population at time t=0, K is the carrying capacity, and r₀ is the base growth rate. The carrying capacity is a theoretical upper bound on the total population that the surrounding environment can support. The figure shows the sigmoid (S-shaped) curve associated with a typical logistic model. <IMAGE>
{Use of Tech} Gone fishing When a reservoir is created by a new dam, 50 fish are introduced into the reservoir, which has an estimated carrying capacity of 8000 fish. A logistic model of the fish population is P(t) = 400,000 / 50+7950e^−0.5t, where t is measured in years.
c. How fast (in fish per year) is the population growing at t=0? At t=5?
Problem 3.9.97d
97–100. Logistic growth Scientists often use the logistic growth function P(t) = P₀K / P₀+(K−P₀)e^−r₀t to model population growth, where P₀ is the initial population at time t=0, K is the carrying capacity, and r₀ is the base growth rate. The carrying capacity is a theoretical upper bound on the total population that the surrounding environment can support. The figure shows the sigmoid (S-shaped) curve associated with a typical logistic model. <IMAGE>
{Use of Tech} Gone fishing When a reservoir is created by a new dam, 50 fish are introduced into the reservoir, which has an estimated carrying capacity of 8000 fish. A logistic model of the fish population is P(t) = 400,000 / 50+7950e^−0.5t, where t is measured in years.
d. Graph P' and use the graph to estimate the year in which the population is growing fastest.
Problem 3.9.13
Find d/dx (In(xe^x)) without using the Chain Rule and the Product Rule.
Problem 3.9.75
75–86. Logarithmic differentiation Use logarithmic differentiation to evaluate f'(x).
f(x) = x^10x
Problem 3.9.77
75–86. Logarithmic differentiation Use logarithmic differentiation to evaluate f'(x).
f(x) = (x+1)¹⁰ / (2x-4)⁸
Problem 3.9.79
75–86. Logarithmic differentiation Use logarithmic differentiation to evaluate f'(x).
f(x) = x^In x
Problem 3.9.80
75–86. Logarithmic differentiation Use logarithmic differentiation to evaluate f'(x).
f(x) = tan¹⁰x / (5x+3)⁶
Problem 3.9.81
75–86. Logarithmic differentiation Use logarithmic differentiation to evaluate f'(x).
f(x) = (x+1)^3/2(x-4)^5/2 / (5x+3)^2/3
Problem 3.9.82
75–86. Logarithmic differentiation Use logarithmic differentiation to evaluate f'(x).
f(x) = x⁸cos³ x / √x-1
Problem 3.9.84
75–86. Logarithmic differentiation Use logarithmic differentiation to evaluate f'(x).
f(x) = (1+x²)^sin x
Problem 3.9.85
75–86. Logarithmic differentiation Use logarithmic differentiation to evaluate f'(x).
f(x) = (1+ 1/x)^x
Problem 3.9.92
Calculate the derivative of the following functions (i) using the fact that bx = exIn b and (ii) using logarithmic differentiation. Verify that both answers are the same.
y = (x²+1)x
Problem 3.9.94
Calculate the derivative of the following functions (i) using the fact that bx = exIn b and (ii) using logarithmic differentiation. Verify that both answers are the same.
y = (4x+1)In x
Problem 3.9.8
Find d/dx(ln(x/x²+1)) without using the Quotient Rule.
Problem 3.9.97b
97–100. Logistic growth Scientists often use the logistic growth function P(t) = P₀K / P₀+(K−P₀)e^−r₀t to model population growth, where P₀ is the initial population at time t=0, K is the carrying capacity, and r₀ is the base growth rate. The carrying capacity is a theoretical upper bound on the total population that the surrounding environment can support. The figure shows the sigmoid (S-shaped) curve associated with a typical logistic model. <IMAGE>
{Use of Tech} Gone fishing When a reservoir is created by a new dam, 50 fish are introduced into the reservoir, which has an estimated carrying capacity of 8000 fish. A logistic model of the fish population is P(t) = 400,000 / 50+7950e^−0.5t, where t is measured in years.
b. How long does it take for the population to reach 5000 fish? How long does it take for the population to reach 90% of the carrying capacity?
Ch. 3 - Derivatives
