How do you determine the point on the line y = 5x + 4 that is closest to the origin?

To find the point on the line y = 5x + 4 that is closest to the origin (0, 0), we can use the concept of distance. The distance D from any point (x, y) to the origin can be calculated using the distance formula:

D = √(x² + y²)

However, since our line is defined by the equation y = 5x + 4, we can substitute y in the distance formula. This gives us:

D = √(x² + (5x + 4)²)

To make our calculations easier and to avoid dealing with the square root, we can instead minimize the squared distance:

D² = x² + (5x + 4)²

Expanding (5x + 4)²:

D² = x² + (25x² + 40x + 16) = 26x² + 40x + 16

To find the minimum distance, we take the derivative of with respect to x:

d(D²)/dx = 52x + 40

Next, we set the derivative to zero to find the critical points:

52x + 40 = 0

Solving for x gives:

x = -40/52 = -10/13

Now that we have x, we can substitute it back into the line equation to find y:

y = 5(-10/13) + 4 = -50/13 + 52/13 = 2/13

Thus, the point on the line y = 5x + 4 that is closest to the origin is (-10/13, 2/13).

In conclusion, the coordinates of the closest point on the line to the origin are:

Point: (-10/13, 2/13)

Leave a Comment