Mathematics 31 10. The slope of the tangent to the graph of the relation xy + y =3 at (2, 1) is A. B. UIN C. 1 D. 2 11. The derivative of y = (4x-3)' (3x-1)2 , in factored form, is A. 2(4x -3)2 (3x -1) -1 B. -6(4x-3)2 (3x-1)-1 C. (x - 9) (3x - 1) -3 ( 4x -3)2 D. 6(2x+1) (3x -1) -3 (4x -3)2 12. Let function f be defined on the interval [ 0, 3 ] as follows: f(x) =4x, where OSx51 f(x) = ax +bx+5, where 1