Trig Functions: Exact Value for Special Angles and Real #'s

Hey everyone, usually I'd do this on my own, but I have many other things to figure out this weekend (the whole college thing is just around the corner). So, I'd like to ask any of you out there that might know how to work through a few problems that I'm... having problems with. Just a brief description of how each one works would be a lot of help, thanks in advance and from now on I promise to pay attention in class :embrsd:

Key: π=Pi θ=Theta √=Square root

A)Find all angles θ, 0≤θ≤2π, for which the following functions are not defined. Explain why. a)secant

B)Find the least positive θ in (1) Degree measure (2) Radian measure for which each is true. a) sin θ = 1/2 b) cos θ = 1/√2 c)tan θ = -√3

C)Find the exact value of all the angles between 360۫ for which sin θ = -√3/2.

Hasta Luego
"L"Chupacabras

This is two weeks old, but I was kinda bored...

A) sec θ = 1/cos θ, therefore any values of cos θ=0, sec θ=undefined. cos θ=0, when θ=π/2 and 3π/2.

B) There are 2 special right triangles. You should know. One is a 30-60-90 (images from Sparknotes, which I only used to find images):

and a 45-45-90:

These are two triangles that always have those proportions. Therefore, sin θ=1/2 would be (in degrees first, then radians)
a)sin 60=1/2, sin π/3=1/2 (radians = degree X π/180)
b)cos 45=1/√2, cos π/4=1/√2
c)This is a little tricky. You need to know quadrants. Quadrant I, II, III, and IV. From Quadrant I to IV, the only trig function that is positive goes in this order: All, Sin Tan Cos. Therefore, the lowest positive number that makes tan θ=-√3 would be the angle 30 in Quadrant II. This would be 30 + 90, or 120.
tan 120=-√3, tan 2π/3=-√3

C)Same right triangles, same quadrants above.

sin θ = -√3/2 would be negative in Quadrants 3 and 4. This would be sin 30 = -√3/2

so 30 in quad 3 is 30 + 180= 210
and 30 in quad 3 is 30 + 270 = 300

so sin 210 and sin 300 both equal -√3/2

I hope i'm not too late. I love trig, it's like second nature to me