Question

Find the point on the line 4x + y = 7 that is closest to the point (-5, 2). (Give your answers correct to two decimal places.)

Answer 1

i clicked the link nothing happened

Answer 2

http://www.dabbleboard.com/draw?b=Guest679849&i=0&c=91f1fdbb51a638a3e9c632f527558ab734e58444

join me there. I will explain

Answer 3

maybe your browser blocked the pop up window. Make sure you allow popups on this page

Answer 4

no the web popped up, but idk how to use the web

Answer 5

Are you using calculus to solve this or can you use something else?
If calculus, then best idea is to use the distance formula. The points on the line will be (x, 7-4x) and the distance between any point on the line and (-5,2) is (x+5)^2 + (7-4x-2)^2 or more simply (x+5)^2+ (5-4x)^2. Expand carefully and you will get a quadratic in x. To find the minimum value, take the derivative, set it = 0 and solve, or just use -b/2a. that will give you the x coordinate of the minimum value, and the y you find by substitution.

Answer 6

ya calculus

Answer 7

ok then that method should work. You have the square of the distance, not the distance, but that is ok. when you expand you get 17x^2-30x+50. Call this f(x) and your derivative is 34x - 30, which is zero when x is 15/17. Makes an ugly decimal which is probably why they asked for two decimal places.

Answer 8

thank you!

Answer 9

welcome!