The equation of perpendicular line on x+3y=7 is 3x−y+λ=0. Since, it is passes through (3,8). ∴ 9−8+λ=0 ⇒λ=−1 ∴ 3x−y−1=0 The point of intersection of lines x+3y=7 and 3x−y−1=0 is (1,2), which is the foot of a point. Let the image of a point (3,8) be (x1,y1). ∴