`{:("खण्ड 'अ'","खण्ड 'ब'"),("1. "int"cosec xdx","(a) "sec^(-1)x+c),("2. "int(dx)/(xsqrt(X^(2)-1)),"(b) "(1)/(2)[xsqrt(a^(2)-x^(2))+a^(2)sin^(-1).(x)/(a)]+c),("3. "intsqrt(a^(2)-x^(2))dx,"(c) "log[x+sqrt(x^(2)+a^(2))]+c),("4. "int(dx)/(sqrt(a^(2)+x^(2))),"(d) "log tan.(x)/(2)+c),("5. "int(dx)/(a^(2)+x^(2)),"(e) "sin^(-1).(x)/(2)+c),(,"(f) "(1)/(a)tan^(-1).(x)/(a)+c):}`

Answer

1. (d), 2. (a), 3. (b), 4. (e), 5. (f).