Use the chain rule to find dz/dt for z = xy³ + x²y + xt² + y + t²

To find the derivative dz/dt using the chain rule, we first need to identify the variables involved. Here, we have z as a function of x, y, and t. So the chain rule tells us that:

dz/dt = (dz/dx)(dx/dt) + (dz/dy)(dy/dt) + (dz/dt)

We will calculate each of these partial derivatives step by step.

Step 1: Calculate Partial Derivatives

  • z = xy³ + x²y + xt² + y + t²
  • dz/dx = y³ + 2xy + t²
  • dz/dy = 3xy² + x + 1
  • dz/dt = 2t

Step 2: Find dx/dt and dy/dt

Next, we need to find the derivatives dx/dt and dy/dt. These derivatives will depend on the relationship between x, y, and t. We need to know how x and y change with respect to t.

Step 3: Combine Using the Chain Rule

Once we have dx/dt and dy/dt, we can substitute everything back into our chain rule equation:

dz/dt = (y³ + 2xy + t²)(dx/dt) + (3xy² + x + 1)(dy/dt) + 2t

This final expression gives us dz/dt in terms of dx/dt, dy/dt, x, y, and t.

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