Question
The curve 3y^2- 3xy +2x^3 = 7 has vertical tangents when:
a. y=x b. y=2x c. 2y=x d. y=3x e. 3y=x
a. y=x b. y=2x c. 2y=x d. y=3x e. 3y=x
Answers
Reiny
6y dy/dx -3x dy/dx - 3y + 6x^2 = 0
dy/dx (6y - 3x) = 3y - 6x^2
dy/dx = (3y-6x^2)/(6y-3x)
the tangent is undefined when the denominator of dy/dx is zero, that is,
6y - 3x = 0
2y = x
dy/dx (6y - 3x) = 3y - 6x^2
dy/dx = (3y-6x^2)/(6y-3x)
the tangent is undefined when the denominator of dy/dx is zero, that is,
6y - 3x = 0
2y = x
Mason
The curve 3y^2 - 3xy + 2x^3 = 7 has vertical tangents when