Question

Determine the sign of cos without using a calculator.

Positive

Negative

Answer 1

cos is positive in fourth quadrant and negative in rest of the three quadrants

Answer 2

It's positive in the first quadrant as well...

Answer 3

yes...sorry

Answer 4

sorry let me re type the question

Answer 5

wow!!

Answer 6

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

Positive

Negative

Answer 7

my fault

Answer 8

so negative correct

Answer 9

positive it's 60 degreees

Answer 10

ohhhh ok

Answer 11

that means first quadrant

Answer 12

Basically:
from
\[[0, \frac{\pi}{2})\ and (\frac{3\pi}{2},2\pi]\]
cosine will be positive

Answer 13

thanks :))))

Answer 14

ACTS... Where the trig functions are positive :)