Originally Posted by Dgeorg6
tan = sin/cos
so d is not true because 295 is in the 3rd quadrant and as you have already written, cos is + in the 3rd quadrant meaning it is >0 not <0
4th quadrant isn't it?
In high school, I remembered this by ASTC - All Students Take Calculus. Starting from the top right quadrant, and working counter clockwise. A=all, S=sin T=tan C=cos. Here's a picture.
If your doing this by finding the equivalent, it is a waste of time. Your thinking too hard.
Since your only dealing with 295 degree, you just need to realize it ends up in the 4th quadrant. In the 4th quadrant, cos are all positive, and thus sec is also positive since sec=1/cos.
d)cos 295<0 is saying that's a negative, but it should be positive from what I just said
Originally Posted by Member 8586
Chad to the rescue! well somewhat lol...ok so
as for b,c,e:
b) sec = 1/cos so 1/positive = positive?
c) tan = sin/cos so negative/positive = negative?
e) csc = 1/sin so 1/negative = negative?
For Cos 116, it lies in 2nd quad, where sin/csc are positive. So cos 116 is negative. That's how simple it is.