The gradient of the line perpendicular to A would be -1/4
What is gradient of a line?
The gradient of a line, often denoted by "m," represents the slope or steepness of the line. It's the ratio of the vertical change (rise) to the horizontal change (run) between any two points on the line
The product of the gradients of perpendicular lines is always -1.
If the gradient of line1 = m and gradient of line2 is m₂, from the perpendicularity theorem
m₁ * m₂ = -1
Given that m₁ = 4
4*m₂ = -1
m₂ = -1/4
Therefore, if the gradient of line A is 4, the gradient of the line perpendicular to A would be -1/4