PDA

View Full Version : Distance between two points SAT Subject test Math



nicole
01-06-2014, 11:37 AM
Distance between two points in 3-D space. SAT Subject test Math level 2

Which of the following is the distance between the points A(1,2,3) and B(-1,-4,0) ?

(A) 4
(B) 5
(C) 6
(D) 7
(E) 8

Thanks!

miranda
01-06-2014, 11:37 AM
The distance between two points A(a_{1}, a_{2}, a_{3}) and B(b_{1}, b_{2}, b_{3}) is given by the following formula:

d=\sqrt{(a_{1}- b_{1})^2+(a_{2}- b_{2})^2+(a_{3}- b_{3})^2}
So, in our case we have
d=\sqrt{(1- (-1))^2+(2- (-4))^2+(3-0)^2}=\sqrt{4+36+9}=\sqrt{49}=7

Therefore the correct answer is (D)

Hope these help!!

nicole
01-06-2014, 11:38 AM
Thank you!!:)