Trigonometric Values - Negative, Larger Numbers

Question

Here's the question- I think from my previous question I got the smaller negative values figured out, but ones with more digits are still confusing me still. Keep in mind, I just selected one; I don't know if it's correct or not and I haven't submitted it yet.

Answer 1

desmos.com/calculator/gjzteeckh5

Answer 2

The sec (-121), the angle is in the 3rd quadrant with a 59 degree reference angle and it is negative. -sec(59) will match, it has the same angle as the reference angle. Since it is in the first quadrant, it is positive. The negative out in front make the signs match. (To check this, you can plug them into a calculator.)

Answer 3

sec(x) = 1/cos(x)

Since cos(–x) = cos(x), this means sec(–x) = sec(x)

Since cos(180 – x) = –cos(x), this means sec(180 – x) = –sec(x)

Hope this helps. Just add a comment if you have any questions.