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  1. Suppose R id (3, 5) and S is (8, -3).  Find each point on the line through R and S that is three times as far from R as it is from S.

 Dec 9, 2014

Best Answer 

 #1
avatar+23254 
+10

I believe that there will be two such points.

One point is 3/4ths of the way from (3,5) to (8,-3).

  To find this point:  the x-distance from 3 to 8 is 5; 3/4ths of 5 is 15/4, or 3.75, adding 3.75 onto 3 is 6.75

                             the y-distance from 5 to -3 is -8; 3/4ths of -8 is -6, adding -6 to 5 is -1

          this point is (6.75, -1)

          Checking:  the distance from 3 to 6.75 is 3.75; the distance from 6.75 to 8 is 1.25; 3.75 = 3 x 1.25

                          the distance from 5 to -1 is -6; the distance from -1 to -3 is -2; -6 = 3 x -2

The other point is past (8,-3).

   To find this point: the x-distance from 3 past 8 must have value 3, the x-distance from 8 away from 3 must                                have value 1.   Dividing the distance from 3 to 8 into 2 parts, each part has value 2.5;                                 add 2.5 onto 8 gives 10.5.

                              the y-distance from 5 to -3 has 2 parts, each part having value -4; add -4 onto -3 gives                                 -7

            this point is (10.5,-7)

          Checking:  the distance from 3 to 10.25 is 7.25; the distance from 8 to 10.25 is 2.25; 7.25 = 3 x 2.25

                          the distance from 5 to -7 is -12; the distance from -7 to -3 is -4; -12 = 3 x -4

 Dec 9, 2014
 #1
avatar+23254 
+10
Best Answer

I believe that there will be two such points.

One point is 3/4ths of the way from (3,5) to (8,-3).

  To find this point:  the x-distance from 3 to 8 is 5; 3/4ths of 5 is 15/4, or 3.75, adding 3.75 onto 3 is 6.75

                             the y-distance from 5 to -3 is -8; 3/4ths of -8 is -6, adding -6 to 5 is -1

          this point is (6.75, -1)

          Checking:  the distance from 3 to 6.75 is 3.75; the distance from 6.75 to 8 is 1.25; 3.75 = 3 x 1.25

                          the distance from 5 to -1 is -6; the distance from -1 to -3 is -2; -6 = 3 x -2

The other point is past (8,-3).

   To find this point: the x-distance from 3 past 8 must have value 3, the x-distance from 8 away from 3 must                                have value 1.   Dividing the distance from 3 to 8 into 2 parts, each part has value 2.5;                                 add 2.5 onto 8 gives 10.5.

                              the y-distance from 5 to -3 has 2 parts, each part having value -4; add -4 onto -3 gives                                 -7

            this point is (10.5,-7)

          Checking:  the distance from 3 to 10.25 is 7.25; the distance from 8 to 10.25 is 2.25; 7.25 = 3 x 2.25

                          the distance from 5 to -7 is -12; the distance from -7 to -3 is -4; -12 = 3 x -4

geno3141 Dec 9, 2014
 #2
avatar+26396 
+5

Suppose R id (3, 5) and S is (8, -3).  Find each point on the line through R and S that is three times as far from R as it is from S

r=(35)s=(83)λ=34x=r+λ(sr) line equation in vector-formx=(35)+34((83)(35))x=(35)+34(58)x=(3+3455+34(8))x=(6.751)

 Dec 9, 2014

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