Subtraction
Finding the difference between two numbers.
- Not commutative or associative.
- Subtracting a negative adds.
- Sign errors send models in the wrong direction.
When to use: Prediction errors, gradient updates, residual computations.
Example: Error = y − ŷ = 10 − 7 = 3. GD step: θ − α · ∇L (negative sign critical).