Harold tried to find all the points on the curve given by xy2−x2y=−54 where the line tangent to the curve is horizontal. This is his solution:Step 1: Finding an expression for dxdy.dxdy=x(2y−x)y(2x−y)Step 2: Forming a system of equations.⎩⎨⎧xy2−x2y=−54x(2y−x)=0y(2x−y)=0Step 3: Solving the system.(6,3)Is Harold's solution correct? If not, at which step did he make a mistake?Choose 1 answer:(A) The solution is correct.(B) Step 1 is incorrect.(C) Step 2 is incorrect.(D) Step 3 is incorrect.
Q. Harold tried to find all the points on the curve given by xy2−x2y=−54 where the line tangent to the curve is horizontal. This is his solution:Step 1: Finding an expression for dxdy.dxdy=x(2y−x)y(2x−y)Step 2: Forming a system of equations.⎩⎨⎧xy2−x2y=−54x(2y−x)=0y(2x−y)=0Step 3: Solving the system.(6,3)Is Harold's solution correct? If not, at which step did he make a mistake?Choose 1 answer:(A) The solution is correct.(B) Step 1 is incorrect.(C) Step 2 is incorrect.(D) Step 3 is incorrect.
Finding Expression for (dy)/(dx): Finding an expression for (dy)/(dx). To find where the tangent line to the curve is horizontal, we need to find where the derivative (dy)/(dx) is equal to zero. Harold's expression for (dy)/(dx) is: (dy)/(dx)=x(2y−x)y(2x−y) We need to verify this by differentiating the given equation xy2−x2y=−54 implicitly with respect to x. Differentiating both sides with respect to x, we get: y2+2xydxdy−2xydxdy−x2dxdy=0 Simplifying, we get: y2−x2dxdy=0 Solving for (dy/dx), we get: (dy/dx)=x2y2 It seems that Harold's expression for (dy)/(dx) is incorrect.
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