juniorGradient Descent
What is a cost function in Gradient Descent?
Updated May 16, 2026
Short answer
A cost function measures how wrong a model’s predictions are.
Deep explanation
Gradient Descent minimizes the cost function, which quantifies error between predicted and actual values. Common examples include Mean Squared Error and Cross-Entropy Loss.
Real-world example
Reducing prediction error in house price estimation models.
Common mistakes
- Confusing cost function with accuracy metric.
Follow-up questions
- What is difference between loss and cost?
- Why square error is used?