So, now let’s look at say if we had a particular one, so let’s actually find them. So say if we have minus these are all in 1 increments. So you can actually say our y intercept is here. We can say ...

Slide 1 of 9, Y equals two x minus five. Minus one is less than or equal to x, which is less than or equal to three., Draw the graph of 𝒚 = 2𝒙 – 5 for values of 𝒙 from -1 to 3.

Each positive gradient is multiplied by the negative gradient to find if any product is -1. ¼ × -4 = -1. Therefore the lines 𝒚 = 𝒙/4 + 3 and 𝒚 = 3 - 4𝒙 are perpendicular.