Find a tangent of the curve y = X3 + 3x2-5, so that the tangent is perpendicular to the straight line 2x-6y + 1 = 0 - (X3 is the third power of X, 3x2 is three times the square of x)

Find a tangent of the curve y = X3 + 3x2-5, so that the tangent is perpendicular to the straight line 2x-6y + 1 = 0 - (X3 is the third power of X, 3x2 is three times the square of x)

The slope of this tangent is - 3
Derivation of curve y '= 3x2 + 6x
Let y '= - 3, the solution is x = - 1, y = - 3,
Let the linear equation be 3x + y + C = 0 and C = 6
So the tangent equation is 3x + y + 6 = 0