Question

f(x) = cos(x)
on the interval [−2π, 2π]

(a) Find the x-intercepts of the graph of
y = f(x).
(Enter your answers as a comma-separated list.)

(b) Find the y-intercepts of the graph of
y = f(x).
(Enter your answers as a comma-separated list.)

(c) Find the intervals on which the graph of
y = f(x)
is increasing and the intervals on which the graph of
y = f(x)
is decreasing. (Enter your answers using interval notation.)

(d) Find the relative extrema of the graph of
y = f(x).
(Enter your answers as a comma-separated list of ordered pairs.)

Answer 1

(a) surely you know where cos(x) = 0
(b) surely you can determine cos(0)
(c) check the graph below
(d) surely you know the min and max of cos(x)

graph at

http://www.wolframalpha.com/input/?i=cos%28x%29

Answer 2

9 8

Answer 3

−2π to 2π where f(x)=cosx

Answer 4

Find the exact zeros of the function
f(x) = 4x2 − 4x − 1.
(Enter your answers as a comma-separated list.)