/ a - b\ |a + b - -----|*(2 + 2*b*(a - b)) \ a + b/
/ b - a\ (2 + 2*b*(a - b))*|a + b + -----| \ a + b/
/ a - b\ (2 + 2*b*(a - b))*|a + b - -----| \ a + b/
(2.0 + 2.0*b*(a - b))*(a + b - (a - b)/(a + b))
/ 2 \ (2 + 2*b*(a - b))*\b + (a + b) - a/ ------------------------------------ a + b
/ 2 \ 2*(1 + b*(a - b))*\b + (a + b) - a/ ------------------------------------ a + b
/ 2 \ 2*(1 + b*(a - b))*\b + (a + b) - a/ ------------------------------------ a + b
/ a - b\ (2 + 2*b*(a - b))*|a + b - -----| \ a + b/
3 3 2 -4*b + 8*b 2 -2 - 2*b + 2*a + 2*b + 6*b - ----------- - 2*a*b + 2*b*a a + b
/ 2 \ / 2 2 \ 2*\1 - b + a*b/*\b + a + b - a + 2*a*b/ ------------------------------------------ a + b