Use reference triangles in an appropriate quadrant to find the angles in Exercises 1–8.
7. c. arcsec(-2)

Use reference triangles in an appropriate quadrant to find the angles in Exercises 1–8.

5. a. arccos(1/2)

Use reference triangles in an appropriate quadrant to find the angles in Exercises 1–8.

5. c. arccos(√3/2)

Use reference triangles in an appropriate quadrant to find the angles in Exercises 1–8.

6. b. arccsc(-2/√3)

Use reference triangles in an appropriate quadrant to find the angles in Exercises 1–8.

7. a. sec^(-1)(-√2)

Use reference triangles in an appropriate quadrant to find the angles in Exercises 1–8.

8. b. arccot(√3)

Find the values in Exercises 9–12.

9. sin(arccos((√2)/2))

Find the values in Exercises 9–12.

11. tan(arcsin(-1/2))

126. Show that the sum arctan(x)+arctan(1/x) is constant.