For any vector $\vec a$, the dot product $\vec a\cdot\vec a$ equals:
A$0$
B$1$
C$|\vec a|^2$
D$2|\vec a|$
Answer & Solution
Correct answer: C. $|\vec a|^2$
a·a = |a||a|cos0° = |a|².
Related questions
Three vectors $\vec a, \vec b, \vec c$ are coplanar if and only if:The cross product $\vec a\times\vec b$ of two parallel non-zero vectors is:The dot product $\vec a\cdot\vec b$ of $\vec a = 2\hat i - \hat j + 3\hat k$ and $\vec b =The magnitude of the vector $\vec a = 3\hat i + 4\hat j$ is:The magnitude of the vector $\hat{i}+\hat{j}+\hat{k}$ is:The value of $\hat{i}\times\hat{j}$ is:The dot product of $(2\hat{i}+3\hat{j}+\hat{k})$ and $(\hat{i}-\hat{j}+\hat{k})$ is:The unit vector in the direction of $3\hat{i} + 4\hat{j}$ is: