# Math Help - trig

1. ## trig

I'd really appreciate it if someone could help me with these problems. I just don't even know where to start. Thanks so much!

1. use the given values to evaluate the remaining trig functions:
cscx = -5
cosx < 0

2. solve for x: [0,2pi] Sin 3x= 1/2

3. rewrite the expression not in fractional form: 1/(csc x + 1)

4. Verify the identity (work on one side only if possible):
sec x - cos x = sin x tan x

2. Well the last question's solution struck to my mind first.
Given to prove:
secx-cosx=sinxtanx
Taking the left hand side:
secx-cosx
=(1/cosx)-cosx
=(1-cos^2x)/cosx
=sin^2x/cosx ((1-cos^2x)=sin^2x)
=(sinx/cosx)sinx
=sinxtanx

3. thank you.. i'm not really following towards the end though.. ugh I'm so frustrated! Can anyone help me with the others../??