Mathematics for IGCSE & O level - Vectors (Section 5 - No. 25)
If a is a vector and k is a scalar, what is the effect of multiplying the vector a by the scalar k?
The magnitude of a is multiplied by |k|.
The direction of a is reversed if k < 0.
The direction of a is changed.
The vector a is always in the positive direction.
解释
The scalar multiplies the magnitude and reverses direction if the scalar is negative.