SOLUTION: is y=-7/8x+3 and -7y=-8x perpendicular

Algebra ->  Graphs -> SOLUTION: is y=-7/8x+3 and -7y=-8x perpendicular      Log On


   

Question 1126473: is y=-7/8x+3 and -7y=-8x perpendicular
Found 2 solutions by josgarithmetic, MathLover1:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
----------------------------------------------
Is y=-7/8x+3 and -7y=-8x perpendicular ?
---------------------------------------------

slopes -7%2F8 versus 8%2F7;

They certainly are (perpendicular).

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
to see is y=-%287%2F8%29x%2B3+ and -7y=-8x perpendicular, first write -7y=-8x in slope-intercept form
y=%28-8%2F-7%29x
y=%288%2F7%29x
compare their slopes:
y=-highlight%28%287%2F8%29%29x%2B3+
y=highlight%28%288%2F7%29%29x
as you can see, highlight%28%288%2F7%29%29 is negative reciprocal of -highlight%28%287%2F8%29%29
or highlight%28%288%2F7%29%29=-1%2Fhighlight%28-%287%2F8%29%29
by definition, lines are perpendicular if their slopes are negative reciprocal to each other