Apply the quotient rule
d(uv) = v du/dx - u dv/dx
dx ----------------------
v^2
du/dx = 6x + 6
dv/dx = 2(x + 1)
v^2 = (x + 1)^4 so we have
dy dx = (x + 1)^2 .* (6x + 6) - (3x^2 + 6x - 7) * 2(x + 1) / (x + 1)^4
= (x + 1) [(6(x + 1)^2 - 2(3x^2 + 6x - 7) ] / (x + 1)^4
= (x^2 + 12x +6 - 6x^2 - 12x + 14 ) / (x + 1)^3
= 20 / (x + 1)^3 Answer
