What is cost function convexity?

Updated May 16, 2026

Short answer

Convexity means the cost function has a single global minimum.

Deep explanation

In convex functions, any local minimum is also global minimum. Gradient Descent works reliably in convex settings because there are no deceptive local minima.

Real-world example

Linear regression optimization.

Common mistakes

  • Assuming all ML loss functions are convex.

Follow-up questions

  • Why is convex optimization easier?
  • Are neural networks convex?

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