Question

Determine the sign of cos pi/3 without using a calculator.

Answer 1

Help please!

Answer 2

well

Answer 3

@amorfide I don't understand :/

Answer 4

you know pi/3 is 60 degrees
draw a cos graph
you know 60 degrees is about .5 and is positive, so it is postive

from the cos graph is shows that angles 0-90 are positive 90-270 are negative

Answer 5

Oh ok thanks!

Answer 6

do you understand? or do you need a better explanation

Answer 7

I think I understand, except what is the cos graph?

Answer 8

you have three graphs
sine graph
cosine graph
tan graph

you have seen them before right?

Answer 9

if not have you seen this diagram before?

Answer 10

No I haven't seen that diagram