Cho \(\left( P \right):\,\,x + y + z + 1 = 0,\,\,\left( Q \right):\,\,2x + y + 3z + 4 = 0\). Khi đó \(\cos \widehat {\left( {\left( P \right);\left( Q \right)} \right)}\) là:
A.\(\dfrac{6}{{\sqrt {42} }}\)
B.\(\dfrac{6}{{\sqrt {41} }}\)
C.\(\dfrac{6}{{\sqrt {43} }}\)
D.\(\dfrac{4}{{\sqrt {46} }}\)
A.\(\dfrac{6}{{\sqrt {42} }}\)
B.\(\dfrac{6}{{\sqrt {41} }}\)
C.\(\dfrac{6}{{\sqrt {43} }}\)
D.\(\dfrac{4}{{\sqrt {46} }}\)
Loga
Hóa Học lớp 12
