Question

Use the dot product to find the magnitude of u if u = 6i - 3j

Answer 1

Vector u :
u = 6 i - 3 j
The magnitude of vector u :
| u | = $\sqrt{6 ^{2}+(-3) ^{2} } = \sqrt{36+9}= \\ \sqrt{45}= \sqrt{9*5}=3 \sqrt{5}$
Answer:
The magnitude of vector u is 3√5.