Asked by Manny

Find the point on the line 6x + y = 9 that is closest to the point (-3,1).
Solution: We need to minimize the function
d = sqrt((x − (−3))^2 + (y − 1)^2)
= sqrt((x + 3)^2 + (y − 1) ^2 )
and, since the point (x, y) lies on the line 6x + y = 9, we can eliminate y from the formula for d:
d = (x + 3)^2 + (9 − 6x − 1) ^2
= (x + 3)^2 + (8 − 6x)^2
It will be easier to minimize the square of the function:
D = d2 = (x + 3)^2 + (8 − 6x)^2
Then,
D

Answers

Answered by MathMate
Yes, continue this way, find the derivative of D with respect to x.
Equate the derivative to zero and solve for x.
Substitute x back into the line equation to find y.
Post you answer for checking if you wish.
There are no AI answers yet. The ability to request AI answers is coming soon!

Related Questions