How do you find the angle between the lines 3x+4y=12 and 4x-3y=12?

1 Answer
May 17, 2018

90

Explanation:

Rearrange so 3x+4y=124y=3x+12y=34x+3

4x3y=123y=4x+12y=43x4

the two gradients are 34and43

34×43=1212=1

so they are perpendicular.