Question

@bibby
Identify the maximum and minimum values of the function y = 8 cos x in the interval [-2π, 2π]. Use your understanding of transformations, not your graphing calculator.

Answer 1

sorry, got distracted with another question

Answer 2

its fine

Answer 3

what are the minimum and maximum values of y=cosx over [-2pi,2pi]?

Answer 4

2 and -2?

Answer 5

1 and -1 http://www.diracdelta.co.uk/science/source/c/o/cosine/image002.gif

Answer 6

so what effect does the 8 have on that?

Answer 7

teh same effect it did 2-3 problems ago. \(af(x)\)
if 0 < a < 1 (a fraction), the graph is stretched horizontally by a factor of a units
if a > 1, the graph is compressed horizontally by a factor of a units.
if a should be negative, the horizontal compression or horizontal stretching of the graph is followed by a reflection of the graph across the y-axis.

Answer 8

so it starts out something like this