Q.10 The Cauchy problem uur + yuy =x with u(x, 1) = 2x, when solved using its characteristic equations with an independent variable t, is found to admit of a solution in the form x = 3 1 se-se, y=e', u= f(s,t). Then f(s, t) = 3 1 1 3 (A) 2 se² +½se (B) ½ se²+se (C)½se-se (D) se-se-t 1 3 3 1 2 2