13. sin150° - 5 cos 300° + 7 tan 225°/tan135° + 3 sin 210°
1) 1
2) 2
3)-2
Answers
150 lis in quadrant II whose reference angle is 30; sin is positive in quadrant II
sin (150) = sin(30) =1/2
300 is in quadrant IV whose reference angle is 60; cos is positive in quadrant IV
cos(300)= cos(60) = 1/2
225 is in quadrant III whose reference angle is 45 ;tan is positive in quadrant III
tan(225) = tan(45)=1
135 is in quadrant II whose reference angle is 45 ;tan is negative in quadrant II
tan(135) = -tan(45)=-1
210 is in quadrant III whose reference angle is 30 ;sin is negative in quadrant III
sin(210) = -sin(30)=-1/2
sin 150 = 1/2
cos 300 = 1/2
tan 225 = 1
tan 135 = -1
sin 210 = -1/2
[Sin150 degress-5cos 300 degrees+7 tan 225 degrees] / [tan 135 degrees + 3 sin 210 degrees]
= (1/2-5/2+7) / (-1-3/2)
= 5 / (-5/2)
= -2