1. Show the calculus to find the critical numbers of f(x) = 6x² - x³. Then use (and show) the Second Derivative Test to determine whether they correspond to local maxima or local minima.
2. A function, f, has a domain of all real numbers.
The 1st derivative is f'(x) = eˣ(x² + 2x + 1) and the 2nd derivative is f''(x) = eˣ(x² + 4x + 3).
You must show all the tests and the value you are testing. Find the following, if they exist. If something doesn't exist, write “none”.
The critical value(s) ____________________
Interval(s) where f is concave upward ____________________
Interval(s) where f is concave downward ____________________
Type of relative extrema and
the x-value where it occurs ____________________
The x-value of any point(s) of inflection ____________________
3. Fill in the blanks and sketch the graph without a calculator. You must use calculus and show work. Find the y-intercept, give open intervals of concavity and list all point(s) of inflection and extrema as ordered pairs. Clearly label your axes and show the characteristics of the function on your graph.
f(x) = x² / (x² - 4), f'(x) = -8x / (x² - 4)², f''(x) = 8(3x² + 4) / (x² - 4)³
Domain of f in interval notation ____________________
y-intercept ____________________
critical number(s) of f ____________________
point(s) of inflection ____________________
concave upward on ____________________
concave downward on ____________________
local extrema ____________________