GATE 2026 MT – Question 32
The value of the scalar triple product $\vec a\cdot(\vec b\times\vec c)$ is ________. (Answer in integer.) Here $\vec a=2\hat i-3\hat j+4\hat k$, $\vec b=\hat i+2\hat j-3\hat k$, and $\vec c=3\hat i+4\hat j-\hat k$, where $\hat i,\hat j,\hat k$ are mutually orthogonal unit vectors.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 36 to 36
Explanation
Compute $\vec b\times\vec c=(10,-8,-2)$. Dotting with $\vec a=(2,-3,4)$ gives $2(10)+(-3)(-8)+4(-2)=20+24-8=36$.
The answer is **36**. Reversing the cross-product order would change the sign.