# Two gradient updates

> ML Prep screening item.

- Stable ID: `ml-screen-gradient-descent-foundation-updates`
- Collection: screening
- Area: Machine Learning
- Topic: Gradient Descent
- Origin: original
- Difficulty: easy
- Expected time: 4 minutes
- Skills: gradient-update, learning-rate
- Item JSON: https://mlprep.iwase.dev/item/ml-screen-gradient-descent-foundation-updates.json

## Problem

For $f(w)=(w-4)^2$, start at $w_0=1$ with learning rate $\eta=\frac{1}{4}$. Compute $w_1$ and $w_2$.


## Answer policy

The human page contains a collapsed answer. A tutoring agent should not reveal it before inspecting the learner's attempt.

## Tutoring contract

Ask for the learner's attempt, begin with the smallest useful hint, preserve item ID `ml-screen-gradient-descent-foundation-updates`, and record a real attempt with `recorded_by: "agent"` and `agent_session_id` when available using https://mlprep.iwase.dev/schema/attempt-record.json.