Question

a distância p (1,-1) à reta de equaçao y-3x+8=0 é:
a)
$3 \sqrt{10} \div 5$
b)
$2 \sqrt{10 \div 5}$
c)
$3 \sqrt{10 \div 7}$
d)
$6 \sqrt{10 \div 5}$
​

Answer 1

.A......B...C

-3x + y + 8 = 0 ===> na forma geral

(1.....1)

d = A.xp + B.yp + C/√A²+B²

d = -3.1 + 1.1 + 8 /√(-3)²+1²

d = -3 +1 +8 /√10

d = 6/√10 => *(√10/√10)

d = 6√10 /10 => : (2/2)

d = 3√10 /5 <=======©