Prove teh Identitiy
from the basic definitions of the hyperbolic functions. Hence, or otherwise show that if x and y satisfy the equations
cosh x cosh y = 2,
cosh x sinh y = -1
then x = -y = +or- ln (1+*squareroot* of 2)
I dunno how to use the math thingy too well so xD sorry if it's messed up.
This question just has me staring, don't even know what I should be doing.