Question

what is the range of f(x)=cos(x)

Answer 1

Look at the graph of cos(x):
http://www.bbc.co.uk/bitesize/higher/maths/images/radians2_graphs01.gif

Answer 2

for range, you need to scan the graph `bottom to top` -
whats the bottom most value in the graph ?
whats the top most value in the graph ?

Answer 3

@linapopp ,
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