Tính cosin của góc giữa hai vectơ \( \overrightarrow a = (4;3;1), \overrightarrow b = (0;4;6) \)?
A.\(\dfrac{{5\sqrt {13} }}{{26}}\).
B.\(\dfrac{{5\sqrt 2 }}{{26}}\).
C.\(\dfrac{{5\sqrt {26} }}{{26}}\)
D.\(\dfrac{{9\sqrt 2 }}{{26}}\).
A.\(\dfrac{{5\sqrt {13} }}{{26}}\).
B.\(\dfrac{{5\sqrt 2 }}{{26}}\).
C.\(\dfrac{{5\sqrt {26} }}{{26}}\)
D.\(\dfrac{{9\sqrt 2 }}{{26}}\).
Loga
Hóa Học lớp 12
