...general, dx , dx I / b\ or I — — — rj-rr = — - sec.~i .r./l -- 1, .* £V(a+&r") '/ — av\ a/' the first of which is real when a is positive ; the second when a is negative : a and b cannot both be negative at the same time. = 1 1 ~ g = - log. where ^/a may...