Problema Solution
A student calculated the distance between the points (2, 3) and (–3, 5).
d = sqrt[( 2 - (-3) )^2 - (3 - 5)^2]
= sqrt[(5)^2 - (-2)^2]
= sqrt(25 - 4)
= sqrt(21)
In two or more complete sentences, explain whether or not the student’s calculation of the distance between the two points is correct.
Answer provided by our tutors
Given the two points (x1, y1) and (x2, y2), the distance between these points is given by the formula:
d = sqrt[(x2 - x1 )^2 + (y2 - y1)^2]
In our case we have x1 = -3, y1 = 5, x2 = 2, y2 = 3
The calculation is not correct because there is "-" instead of "+" in the expression, that is:
d = sqrt[( 2 - (-3) )^2 - (3 - 5)^2] should be d = sqrt[( 2 - (-3) )^2 + (3 - 5)^2].