Math
posted by Jon on .
1)Find cos theta if sin theta=3/5 and 90 degrees<theta<180 degrees.
A)4/5
B)4/5
C)square root of 34/5
D)square root of 34/5
I chose A
2)Simplify:1csc^2theta/cot^2theta
A)1
B)1
C)tan^2theta
D)1/sin^4theta
I chose C
3)Simplify:5(cot^2thetacsc^2theta)
A)5
B)5
C)5csc^2 theta
D)5csc^2 theta
I chose B
4)Which expression is not equivalent to 1?
A)sin^2theta+cot^2thetasin^2theta
B)sin^2theta/1costheta 1
C)sec^2theta+tan^2theta
D)cot^2thetasin^2theta/cos^2theta
I don't know
5)Which expression is equivalent to tan thetasec theta/sin theta?
A)cot theta
B)cot theta
C)tan thetacot theta
D)tan thetasec^2theta
I don't know

Are you studying for a trig test?
Just curious!
Where is your effort?
Why do you not try to solve each question and show your work?
Then we can help you better.
I would like to know if you are preparing for a math state test. 
I have been showing my work in my book but not for these questions b/c I have no clue as to how to solve them its just I need them to be checked and its just too time consuming to post the work on the computer. I really appreciate everyone's help.

Thank you for being honest.
I don't mind helping you when there is time. However, I will only solve one or two questions and allow others to do the rest. 
Thank you

I am willing to do one just to show you how. Express all functions as sin and cos, for example tan = sin/cos and then remember that sin^2 + cos^2 = 1
4)Which expression is not equivalent to 1?
A)sin^2theta+cot^2thetasin^2theta
B)sin^2theta/1costheta 1
C)sec^2theta+tan^2theta
D)cot^2thetasin^2theta/cos^2theta
I don't know
A)> sin^2 T ( 1 + cos^2 T/sin^2T)
= sin^2T+ cos^2 T = 1
B) > sin^2 T/(1cos T)  1
= sin^2 T (1+cos T)/(1cos^2T)  1
= 1 + cos T  1
this is not 1
C) > 1/cos^2 T + + sin^2/cos^2 T
= (1+sin^2 T)/cos^2T
that is not 1 either, but I bet you have a typo in the original sign
D) > cot^2thetasin^2theta/cos^2theta
= (cos^2 T sin^2T)/(sin^2 T cos^2 T)
= 1