The answer for part be is no but I cannot figure out why. Can you please tell me where I did wrong?

Consider the curve C: y = (x + 4)2 + AlW (x -4)', where x > -4. dy (a) Find dx Explain (b) Someone claims that two of the tangents to C are perpendicular to the straight line x - 6y + 7 =0. Do you agree? Explain your answer.( a ) dy d d'x ax [ ( x + 4 ) * + 4 (x-4) 37 = 3 3 2 (x+4 + 2 (x-4 ( b ) 3. [( c+ 4 ) = + ( x - 4) ] x (- ) = - 1 ( x+4 )2 = -4-x+4 * + 4 = x2 X = 2. 562 or - 1.562 yes I agree