Is this true or false?

Question

True or false.   If a line L1 has equation y = mx + b, where m and b are constants with m ≠ 0,then an equation of a line L2 perpendicular to L1 has the form  y=-1/m x+C, where C is a constant.   

 

If you think the statement is true, then prove it. On the other hand, if you think the statement is false, then give an example that disproves the statement.

Answer 1

What you need to know is that the product of the slopes of two linear equations is equal to -1 if and only if the two lines intersect at a right angle. In other words, the two lines are perpendicular to each other.

 

Now, if you multiply m with -1/m you certainly obtain -1 for all values of m not equal to zero.