
Patrick B. answered 12/10/20
Math and computer tutor/teacher
the formula is:
(b x1 + a x2)/(a+b)
(b y1 + a y2) /(a+b)
x1=-3
x2=6
y1=-2
y2=1
a=2
b=1
(1*-3 + 2*6)/3 = (-3 + 12)/3 = 9/3 = 3
(1* -2 + 2 * 1)/3 = ( -2 + 2)/3 = 0
A(-3,-2) P(3,0) B(6,1)
check:
AP = sqrt( 6^2 + 2^2) = sqrt(36+4) = sqrt(40) = 2*sqrt(10)
PB = sqrt( 3^2 + 1^2) = sqrt(10)
AP/PB = 2/1
to find the other point, reverse the values of A and B, so
that the ratio is 1 to 2
x1=-3
x2=6
y1=-2
y2=1
a=1
b=2
and again for your convenience,
the formula is:
(b x1 + a x2)/(a+b) for the X coordinate of point P
(b y1 + a y2) /(a+b) for the Y coordinate of point P
(2 * -3 + 1 * 6)/3 = (-6+6)/3 = 0
(2* -2 + 1*1)/3 = (-4+1)/3 = -3/3 = -1
(0,-1)
A (-3,-2) P(0,-1) B(6,1)
AP = sqrt( 3^2 + 1^2) = sqrt(10)
PB = sqrt( 6^2 + 4^2) = sqrt(40) = 2*sqrt(10)
AP/PB = 1/2