Question

Hyperbola
I'm focusing why don't we apply sinh to euclidean triangle and why circular sin and cos works only inn Euclidean

Answer 1

@perl :)

Answer 2

@satellite73

Answer 3

I mean the definition of sinh(x) for unit HP If I put x= pi/2, it won't give me 1as by using circle sin(x).
I know that should be imaginary factor, but in the proof of sinh and sin we used the same triangle !