FIND EXACT TRIG VALUES!?

Question

1. cos * pi/ 4

2. sin * pi/ 6

3. cos * pi/2

4. tan * pi/4

5. sin * pi/3

6. cot * pi/2

7.csc *-7pi/ 3

8. sec * -3pi/4

HELP WITH THESE EXPLANATION AND ANSWER????

Answer 1

Those are radians, it is just as easy to find the answers as with degrees (a full circle of 360 degrees is 2pi radians).  If you have a graphing calculator, you can switch it to radian mode.  I personally like to use the unit circle when they are all this simple. (In the unit circle, the x value is cos and the y value is sin)

1. cos(pi/4 or 45 deg) = sqrt(1/2) or about .7071

2. sin(pi/6 or 30 deg) = 1/2

3. cos(pi/2 or 90 deg) = 0

4. tan(pi/4) = 1 [tan = sin/cos]

5. sin(pi/3 or 60 deg) = sqrt(3)/2 or about .8660

6. cot(pi/2) = 0 [cot = 1/tan]

7. csc(-7pi/3 or 300 deg) = -2/sqrt(3) or about -1.1547 [csc = 1/sin, -7pi/3 = -pi/3 = 5pi/3]

8. sec(3pi/4 or 135 deg) = -sqrt(1/2) or about -.7071 [sec = 1/cos]

Answer 2

You need them in degree form.