The equation of a straight line passing through two points (x¹, y¹) and (x², y²) is:-
y — y¹ = {(y² — y¹)/(x² — x¹)}(x — x¹)
We have (x¹, y¹) = (—2, 8) and (x², y²) = (4, —4)
So the equation becomes
y — 8 = { —4 —8)/(4 —(—2))}[x — (—2)]
=> y — 8 = (—12/6)(x + 2)
=> y — 8 = — 2 ( x + 2) = — 2 x — 4.
=> 2 x + y — 4 = 0.
The equation of the straight line is
y = — 2 x + 4.
The gradient of the straight line = — 2. The straight line lies in second, first and fourth quadrant making an angle 116.6° with the postive direction of X-axis.
