Hi, it would be great if someone could give me explanations for how to solve this species of math problem:

Jedithious:

Hi, it would be great if someone could give me explanations for how to solve this species of math problem:

Write an expression for the distance between each pair of points (in terms of coordinate geometry).
a) (a, b) and (2a, 2b)
b) (x, 2y) and (2x, -y)
c) (m + 1, n - 1) and (m - 1, 2n - 1)
d) (2p, -p) and (4p, 3p)

Hi Jedithious,
You just have to use the distance formula. It looks horrible but it is just from pythagoras' theorem.
I don't remember the formula, I just remember where it comes from.
I have just done this sketch to help you understand.
Do you actually need me to answer one of the questions as well or would you like to try yourself first?

distance formula.JPG

Jedithious:

Hi, it would be great if someone could give me explanations for how to solve this species of math problem:

Write an expression for the distance between each pair of points (in terms of coordinate geometry).
a) (a, b) and (2a, 2b)
b) (x, 2y) and (2x, -y)
c) (m + 1, n - 1) and (m - 1, 2n - 1)
d) (2p, -p) and (4p, 3p)

a) d= sqrt[ (2a-a) ² + (2b-b) ² ] ==> sqrt [ a ² + b ² ]

I've just done 1 try the others yourself and I will check your answers if your want.

Hi Melody,

Thank you, its simpler than I suspected.
Yes, checking would be appreciated

b) sqrt [ x^2 + 9y^2 ]
c) sqrt [ 4 + n^2 ]
d) sqrt [ 20p ]

Jedithious:

Hi Melody,

Thank you, its simpler than I suspected.
Yes, checking would be appreciated

b) sqrt [ x^2 + 9y^2 ] correct
c) sqrt [ 4 + n^2 ] correct
d) sqrt [ 20p ]

I don't think that d is quite right,