07 coordinate geometry

Question 1

midpoint of ab

Answer 1

(x1+x2 / 2, y1+y2 / 2)

Question 2

gradient of ab

Answer 2

tan A, where a = angle of inclination

Question 3

if l1 // l2

Answer 3

gradients are euqal

Question 4

if l1 perpendicular to l2

Answer 4

product of gradients = -1

Question 5

eqn on non vert line

Answer 5

y - y1 = m (x - x1)

Question 6

area of rectilinear figures

Answer 6

anticlockwise direction
down wards arrow = +ve, upwards arrow = -ve