3. Tentukan persamaan garis yg melalui titik (4, -1) dan tegak lurus dengan persamaan : a. y = -5x + 1 b. x = 2y + 5 c. 3x - 5y = 5 d. 4y + 3x - 8 = 0 4. Jika d

karena tegak lurus maka m1.m2 = -1
terlebih dahulu kita mencari m1
a. m1 =-5
m2= 1/5
y-y1=m(x-x1)
y-(-1)= 1/5(x-4)
y+1 = 1/5x -4/5
y= 1/5x - 4/5-1
y= 1/5x -9/5

b. m1= 1/2
m2= -2
y-y1=m(x-x1)
y-(-1)=-2(x-4)
y+1 =-2x+8
y= -2x+7

c. m1 = 3/5
m2 = -5/3
y-y1=m(x-x1)
y-(-1)=-5/3(x-4)
y+1 =-5/3x +20/3
y= -5/3x + 20/3 -1
y= -5/3z +17/3

d. m1 =-3/4
m2 = 4/3
y-y1=m(x-x1)
y-(-1)= 4/3(x-4)
y+1 = 4/3x -16/3
y= 4/3x -19/3

4. m1 = -12/8 = -3/2
a. sejajar (-4, -3)
m1= m2
y-y1=m(x-x1)
y-(-3)=-3/2(x-(-4))
y+3=-3/2x-6
y= -3/2x - 9

b. tegak lurus (-4, -3)
m1.m2= -1
-3/2.m2 = -1
m2 = 2/3
y-y1=m(x-x1)
y-(-3)=2/3(x-(-4))
y+3=2/3x+8/3
y= 2/3x-1/3