Find the derivative of the function y = arctan 3x - 9 7(x2+ 2) O + x + 49 ( 2 + 2 ) 2 O 6+18x -3x2 + (x2+ 2) 2 + O ( + 7) 2 x 2 + 4 O 6+18x - 3x2 x + 49 (2 2+ 2) 2 6-18x - 3x2 x + 49 (12+ 2)2