Question

Give an example of a real number t for which cos t Is positive and sin t is negative

Answer 1

we loook at our trusty unit circle
(cos,sin)
so we need a point that has a positive x but negative y
4th quadrant
an exmplie is 11pi/6

t=11pi/6
cos(11pi/6)=(√3)/2
sin(11pi/6)=-1/2