Engineering Board Exam Reviewer · Vector Algebra: Dot and Cross Products · medium

Find A× B if A= i + 2, j + 3, k and B=2, i - j + k.

1. 5, i + 5, j - 5, k
2. -5, i - 5, j + 5, k
3. 5, i - 5, j - 5, k
4. 5, i + 5, j + 5, k

Answer

A. 5, i + 5, j - 5, k

Solution

A× B= vmatrix i& j& k\1&2&3\2&-1&1 vmatrix=(2+3) i-(1-6) j+(-1-4) k=5 i+5 j-5 k.

More Vector Algebra: Dot and Cross Products questions

1. Find the magnitude of A=2 i-2 j+ k.
2. Find A· B if A=2, i + 3, j - k and B= i - 2, j + 4, k.
3. Find a unit vector perpendicular to both A=2 i- j+ k and B= i+2 j- k.
4. Find the volume of the parallelepiped with edges A= i+2 k, B=3 j+ k, and C=2 i+ j.
5. Find the scalar projection of A=3 i+4 j onto B= i+2 j+2 k.
6. Find the area of the parallelogram whose adjacent sides are A=3 i+ j+2 k and B= i- j+2 k.
7. Find the angle between A= i+2 j+2 k and B=2 i- j+2 k.

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