Question

Sejam as retas : r: x – 7 s: -1/3x + 3 t= 3x – 5 u: 3x + 6
Qual é a posição relativa entre as retas (paralela, concorrente, perpendicular)
a) r e t
b) t e u
c) u e s

Answer 1

$\left[\begin{array}{cc}1&-7\\3&-5\/\end{array}\right]$ = -5 + 21 = 16

1 . 3 diferente de -1, logo concorrente

B)

$\left[\begin{array}{cc}3&-5\\3&6\\\end{array}\right]$ = 18 + 15 = 33

3 . 3 diferente de -1, concorrente

C)

$\left[\begin{array}{cc}3&6\\-1/3&3\\\end{array}\right]$ = 9 + 2 = 10

3 . (-1/3) = -3/3 = -1

Perpendicular