i need to find the tan(a-b) knowing tan a=5/12, sin $= -4/5 and sec B= 25/24 the restriction is (pi/2)

Question

i need to find the tan(a-b) knowing tan a=5/12, sin $= -4/5 and sec B= 25/24 the restriction is (pi/2)<$<a<(3pi/2)<B<2pi. This is for precalc class and is kind of my last resort... I don't know how this site works actually, but please help ^^

anonymous · Answer

what is dollar here?
I guess you should use the fact that tan(a-b)=(tanA-tanB)/(1+tanAtanB)

anonymous · Answer

sorry i didn't have a theta so i just put that instead. !! I used that but i keep getting the wrong answer so feel like im doing it wrong. Supposedly the answer is 204/253... D:

anonymous · Answer

how did you use sin(theta)=-4/5 ? I cannot see how it can be.

anonymous · Answer

i didn't use it because i didn't think it was important to the equation D:

anonymous · Answer

ok than how did you find out sin a?

anonymous · Answer

i drew a triangle and used pythagorean to find the other side. Why do i need the sin? it's not even in the problem... is it?

anonymous · Answer

If you find sin a than you are basically done, but it is not necessary I guess.

anonymous · Answer

I feel bad now, I am doing calculus now, but I would not be able to solve this :(

anonymous · Answer

it's ok i fail even more XD

anonymous · Answer

try posting it again, hoping some wiser guy will help you

anonymous · Answer

ok then thanx anyway ^^