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Multiple Choice
Find an equation of the tangent plane to the surface at the point .
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Verified step by step guidance
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Step 1: Recall the general formula for the equation of the tangent plane to a surface z = f(x, y) at a point (x₀, y₀, z₀). The formula is given by: z - z₀ = fₓ(x₀, y₀)(x - x₀) + fᵧ(x₀, y₀)(y - y₀), where fₓ and fᵧ are the partial derivatives of f with respect to x and y, respectively.
Step 2: Compute the partial derivative of the given surface z = x² + y² with respect to x. This gives fₓ(x, y) = ∂/∂x(x² + y²) = 2x.
Step 3: Compute the partial derivative of the given surface z = x² + y² with respect to y. This gives fᵧ(x, y) = ∂/∂y(x² + y²) = 2y.
Step 4: Evaluate the partial derivatives at the given point (1, 2). For fₓ(1, 2), substitute x = 1 and y = 2 into fₓ(x, y) = 2x, resulting in fₓ(1, 2) = 2(1) = 2. Similarly, for fᵧ(1, 2), substitute x = 1 and y = 2 into fᵧ(x, y) = 2y, resulting in fᵧ(1, 2) = 2(2) = 4.
Step 5: Substitute the values x₀ = 1, y₀ = 2, z₀ = 5, fₓ(1, 2) = 2, and fᵧ(1, 2) = 4 into the tangent plane formula z - z₀ = fₓ(x₀, y₀)(x - x₀) + fᵧ(x₀, y₀)(y - y₀). Simplify the equation to find the tangent plane: z = 2(x - 1) + 4(y - 2) + 5.