What is the geometric effect of scalar multiplication when the scalar is negative?
Conditions
- Scalar
- Non-zero initial vector
Reasoning, step by step
- Calculate the new length as original length times .
- Reverse the direction of the vector by 180 degrees.
- Combine these effects to form the scaled vector.
Example
Multiplying by results in , which points left instead of right.
Common misconceptions
- Thinking the vector shrinks to zero if the scalar is negative.
- Confusing sign change with rotation other than 180 degrees.
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