Math 5A Practice Final
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Math 5A
Practice Final
1. Compute the indicated derivative of each of the following functions (you don’t have to simplify your answers).
(a) (4 points) If f (θ) = tan2 (sin(θ)), find f ′ (θ).
(b) (4 points) If g(x) = cos(3x), find the 50th derivative g(50) (x). (Hint: Look for a pattern, don’t do all 50 derivatives one-by-one).
(c) (4 points) If h(t) = (arctan t)(ln t) + arctan(ln t), find h′ (t).
(d) (4 points) If m(u) = ╱ 、4 , find m′ (u)
2. Find the derivative f ′ (x) for each of the following functions (you don’t have to simplify your answers). (a) (4 points) f (x) = ln(ln(ln(ln(x))))
(b) (4 points) f (x) =′sec(eα )
(c) (4 points) f (x) = (x2 + x - 3)α (hint: logarithmic differentiation)
3. Suppose T = f (t), where T is the temperature (』F) of a baked lasagna taken out of a hot oven, and t is the number of minutes since the lasagna has been out of the oven.
(a) (2 points) What are the units for the derivative f ′ (t)?
(b) (2 points) What are the units for the second derivative f′′ (t)?
(c) (1 point) Would you expect the derivative f ′ (t) to be positive or negative? Please justify.
(d) (1 point) Would you expect the second derivative f′′ (t) to be positive or negative? Please justify. (Hint: if you were to graph f (t), what would its shape be?)
4. Evaluate each of the following limits.
x2 - 3x + 2
α →2 x2 - 7x + 10
(b) (4 points) lim
(c) (4 points) lim x2 eα
α → -~
(d) (4 points) lim
1
(e) (4 points) lim e z
α →0+
5. For each part of this problem:
· Find all horizontal asymptotes of f (x), if any.
· Find all vertical asymptotes of f (x), if any.
(a) (10 points) f (x) = ,
e2α
(b) (10 points) f (x) =
6. (10 points) Show that there is at least one root of the equation 2-α = in the interval (1, 3).
7. The half-life of cesium-137 is 30 years. Suppose we have a 100-mg sample
(a) (8 points) Find an expression for the mass remaining after t years.
(b) (4 points) How much of the sample remains after 100 years? (You do not have to simplify to a single number.)
(c) (4 points) After how long will only 1 mg remain? (You do not have to simplify to a single number.)
8. Our goal in this exercise is to approximate ,25.03.
(a) (1 point) For what value of a would ,a ● ,25.03? Evaluate ,a at this value.
(b) (5 points) Use linear approximation to approximate ,25.03.
(c) (4 points) Use a Taylor polynomial of order 3 to approximate ,25.03 (Note: you may leave your answer as an expression).
9. (10 points) Find through implicit differentiation. tan(x - y) =
10. For f (x) = ln(x2 + 3),
(a) (5 points) Find all intervals of increase and decrease, and determine any local extrema.
(b) (5 points) Determine the intervals where f (x) is concave up and where it is concave down. Also determine the inflection points, if any.
(c) (5 points) Sketch a graph of the function, using the previous parts of the problem.
11. (10 points) Sketch the graph of a function f (x) with the following properties:
· increasing on (-≈ , -10) and (1, ≈), and decreasing on (-10, 1)
· concave down on (-≈ , -4) and (5, ≈), and concave up on (-4, 5)
· lim f (x) = 10.
→ ~
12. (10 points) The sum of two positive numbers is 15. What is the smallest possible number of the sum of their squares?
2022-03-17