The function f(x)=x2/a,    0≤x<1a,    1≤x<22b2−4b/x2,    2≤x<∞ Is continuous for 0≤x<∞, then the most suitable values of a and b are

f(x) is continuous at x=1.∴           f(1−0) = f(1)=f(1+0)⇒         1/a=a⇒a=±1.             f(x) is continuous at x=2.∴          f2−0=f2=f2+0⇒       a=2b2−4b/2⇒b2−2b=2When  a=−1,b2−2b=−1⇒b−12=0⇒b=1.When  a=1,b2−2b=1⇒b=1±2Which are not given.Hence (3)is the correct answer.