Question

Ditentukan 2 buah garis.gris m melalui titik (2,1) dan titik (8,a) dan garis n bergradien 1/2.
a)tentukan nilai a,jika garis m sejajar dg garis n.!
b)tentukan nilai a,jika garis m tegak lurus dg garis n.!

Answer 1

A) m1 = m2 = ½
m = (y2 - y1) / (x2 - x1)
½ = (a - 1) / (8 - 2)
½ = (a - 1) / 6
(½ × 6) = (a - 1)
3 = a - 1
a = 3 + 1 = 4

b) m1 . m2 = -1
m2 = -1 / ½
m2 = -1 × 2/1 = -2
m = (y2 - y1) / (x2 - x1)
-2 = (a - 1) / (8 - 2)
-2 = (a - 1) / 6
-2 . 6 = a - 1
-12 = a - 1
a = -12 + 1 = -11