Final answer:
The points at which the relation has a horizontal tangent line are found where the derivative is zero. To find these points, take the derivative of the function and set it equal to zero. Solve the resulting equation to find the x-values of the points.
Step-by-step explanation:
The point(s) at which the relation has a horizontal tangent line are found where the derivative is zero. This means that the slope of the curve is zero at these points. In other words, the function is neither increasing nor decreasing at these points.
To find these points, you need to take the derivative of the function and set it equal to zero. Solve the resulting equation to find the x-values of the points.
For example, let's say the function is f(x) = x^2 - 4x + 3. Take the derivative of this function to get f'(x) = 2x - 4. Set f'(x) = 0 and solve the equation 2x - 4 = 0. The solution is x = 2. So, the point (2, f(2)) is a point where the function has a horizontal tangent line.