Let y = f(x) be the particular solution to the differential equation "=-7xy, with the initial condition f(1) = -1. Which of the following gives an expression for f(x) and dx the domain for which the solution is valid? Of ( x ) = 1 for (- co, - 16) and (16, co) V7x2 -6 1 Of ( x ) = -1 for (- oo, - 6 and ,00 ) V7x2 -6 7 Of ( x ) = -. 1 for (- oo, - V6) and (16, co) V7x2 -6 1 6 Of ( x) = for (- oo, - 6 and (, ,00 ) V V7x2 -6