trignomotry?

Question

eliminate @:
1. x=b tan@, y=a sec@
2. x=tan@ y=a sin@
3. x=sin@+ cos@, y=sin@-cos@

cheers

Answer 1

1. Using the identity: (tan x)^2 + 1 = (sec x)^2
x^2=b^2 (tan@)^2 and y^2=a^2 (sec@)^2

then rearrange to get: (tan@)^2 as the subject and (sec@)^2 as the subject. By taking one away from the other, this implies:
x^2/b^2-y^2/a^2= -1

Answer 2

1.
y^2/a^2 - x^2/b^2=1
it is an hyperbola

2.(got a little trouble with this)
a^2*x^2 - x^2*y^2 - y^2 = 0
some sort of weird curve

3.(this was my favorite)
x^2 + y^2 = 2
it's a circle

i have the procedures in paper if u want them..

Answer 3

I think it's trigonometry

Ana