55,258 views
22 votes
22 votes
Let y be differentiable with respect to x. For the relation x³ + y³ = 9xy, find dy/dx by

implicit differentiation

User Sachin Chavan
by
3.1k points

2 Answers

14 votes
14 votes

Answer


(dy)/(dx)

Explanation:

Your welcome ;)

22 votes
22 votes

Answer: (3y² * dy/dx + 3x² * dy/dx - 9y) / 9.

Step-by-step explanation: To find dy/dx for the relation x³ + y³ = 9xy, we can use the chain rule. The chain rule states that if y is a function of x and x is a function of t, then the derivative of y with respect to t is equal to the derivative of y with respect to x times the derivative of x with respect to t.

In this case, we are given that y is a function of x and we want to find the derivative of y with respect to x. To do this, we can rewrite the given equation as follows:

x³ + y³ = 9xy

y³ = 9xy - x³

We can then take the derivative of both sides of the equation with respect to x to find dy/dx as follows:

3y² * dy/dx = 9y + 9x * dy/dx - 3x² * dy/dx

3y² * dy/dx = (9y + 9x * dy/dx) - 3x² * dy/dx

0 = (9y + 9x * dy/dx) - (3y² * dy/dx + 3x² * dy/dx)

0 = 9y + 9x * dy/dx - 3y² * dy/dx - 3x² * dy/dx

We can then solve this equation for dy/dx as follows:

0 = 9y + 9x * dy/dx - 3y² * dy/dx - 3x² * dy/dx

9x * dy/dx = 3y² * dy/dx + 3x² * dy/dx - 9y

9x * dy/dx = 3y² * dy/dx + 3x² * dy/dx - 9y

dy/dx = (3y² * dy/dx + 3x² * dy/dx - 9y) / 9x

dy/dx = (3y² * dy/dx + 3x² * dy/dx - 9y) / 9x

Therefore, the derivative of y with respect to x for the given equation is equal to (3y² * dy/dx + 3x² * dy/dx - 9y) / 9.

User Mark Fraser
by
3.2k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.