SOLUTION: If the line (b^2-1)x-(b+1)y=b is perpendicular to the line x+2y=1, then find the value of b.

Algebra ->  Functions -> SOLUTION: If the line (b^2-1)x-(b+1)y=b is perpendicular to the line x+2y=1, then find the value of b.      Log On


   

Question 1005247: If the line (b^2-1)x-(b+1)y=b is perpendicular to the line x+2y=1, then find the value of b.
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
The slopes, %28b%5E2-1%29%2F%28b%2B1%29 and -1%2F2, must be able to form a product of -1. The solved value for b will make the two lines perpendicular.

%28b%5E2-1%29%2F%28b%2B1%29=2

b%5E2-1=2b%2B2

b%5E2-2b-3=0, factorable.

%28b%2B1%29%28b-3%29=0

You WANT the slope of the first equation to be 2.
b=3 will work, but b=-1 will not work.