Math Is Fun Forum

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Find Coordinates of Point B

Plot the points A = (-1, 8) and M = (2, 3) in the xy-plane. If M is the midpoint of a line segment AB, find the coordinates of B.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,626

Re: Find Coordinates of Point B

Use the same vector method in the previous post.

B

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Find Coordinates of Point B

Use the same vector method in the previous post.

B

I don't know the vector method. I haven't played around with vectors in over a decade.

Plot the points A = (-1, 8) and M = (2, 3) in the xy-plane. If M is the midpoint of a line segment AB, find the coordinates of B.

I know the distance from A to M = M to B.

Can the distance formula be used?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,626

Re: Find Coordinates of Point B

Distance would be hard because you don't know the direction. I've given two ways in the other post.

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

amnkb

Member

Registered: 2023-09-19

Posts: 253

Re: Find Coordinates of Point B

Plot the points A = (-1, 8) and M = (2, 3) in the xy-plane. If M is the midpoint of a line segment AB, find the coordinates of B.

just plug into midpoint formjula

Set the x and y coords equal

Solve for x and y

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Find Coordinates of Point B

Plot the points A = (-1, 8) and M = (2, 3) in the xy-plane. If M is the midpoint of a line segment AB, find the coordinates of B.

just plug into midpoint formjula

Set the x and y coords equal

Solve for x and y

You are so kind.

(x + 1)/2 = 2

x + 1 = 2(2)

x + 1 = 4

x = 4 - 1

x = 3

(y - 8)/2 = 3

y - 8 = 6

y = 14

So, point B = (3, 14).

Yes?

Last edited by mathxyz (2024-03-23 02:26:28)

Bob

Administrator

Registered: 2010-06-20

Posts: 10,626

Re: Find Coordinates of Point B

(x + 1)/2 = 2

x + 1 = 2

x = 1

line 2 should be x + 1 = 4

14 is right.

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

mathxyz

Member

From: Brooklyn, NY

Registered: 2024-02-24

Posts: 1,053

Re: Find Coordinates of Point B

(x + 1)/2 = 2

x + 1 = 2

x = 1

line 2 should be x + 1 = 4

14 is right.

Bob

I edited my post.

Point B = (3, 14).

Last edited by mathxyz (2024-03-23 02:27:13)