SOLUTION: write an equation of a line (standard form) passing through A (-3,5) and perpendicular to a line passing through C (6,2) and D (1,3) help...

Algebra ->  Functions -> SOLUTION: write an equation of a line (standard form) passing through A (-3,5) and perpendicular to a line passing through C (6,2) and D (1,3) help...      Log On


   

Question 1084204: write an equation of a line (standard form) passing through A (-3,5) and perpendicular to a line passing through C (6,2) and D (1,3)
help...
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The line through C (6,2) and D (1,3)
has slope [ change in y ] / [ change in x ]
+m+=+%28+3+-+2+%29+%2F+%28+1+-+6+%29+
+m+=+1+%2F+%28-5%29+
--------------------
Any line perpendicular to this line
will have slope =
+m%5B1%5D+=+-1%2Fm+
+m%5B1%5D+=+-1%2F%28+-1%2F5+%29+
+m%5B1%5D+=+5+
----------------------------
The unknown line goes through A( -3,5 )
I can use the general point-slope formula
+%28+y+-+5+%29+%2F+%28+x+-%28-3%29+%29+=+5+
+%28+y+-+5+%29+%2F+%28+x+%2B+3+%29+=+5+
+y+-+5+=+5%2A%28+x+%2B+3+%29+
+y+-+5+=+5x+%2B+15+
+5x+-+y+=+-20+
----------------------
Check:
Does it go through A( -3,5 ) ?
+5%2A%28-3%29+-+5+=+-20+
+-15+-+5+=+-20+
+-20+=+-20+
OK