Originally Posted by
andyboy179 ??
year11, my final year, i've completed my GCSE in maths and im now doing additional maths
Oh boy...ok, Andy, I'll temporarily believe that you're in a class of 70 (outch!) plus you have a
teacher that does not allow students to take notes...
SLOPES
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The slope of line2 perpendicular to line1 is the reciprocal of line1's slope, multiplied by -1.
This simply means you "flip over" the fraction representing line1's slope, and change its sign:
"change its sign" means change to - if it was a +, change to + if it was a -.
Keep in mind that ALL numbers are fractions: like 3 is a fraction: 3/1 ;
the /1 is implied (not shown).
So if line1 has slope of +5, then line2 will have slope of -1/5:
flip over +5/1 to get +1/5, change sign: -1/5.
Here's a few examples, Line2 being perpendicular to line1:
Code:
Line1 Line2
7 -1/7
63 -1/63
-7 1/7
-63 1/63
1/7 -7
1/63 -63
2x/y -y/(2x)
-(2x+y) 1/(2x+y)
pi -1/pi
Now give copies of this to your 70 classmates...and don't tell the teacher !