For STEM students
Find your firstmistake
You have been stuck on question four for forty minutes. The answer in the back is 2x·cos(x²), yours is not, and nothing in the worked example tells you which line broke.
LearnFastAI reads your working and tells you exactly which line broke, and which rule you missed on it — then asks you the one question that gets you unstuck.
It stops short of writing the final answer for you. That part is yours.
Windows 10 & 11 · Free · No card required
- 1f(x) = \sin(x^2)
- 2\text{let } u = x^2 \quad\Rightarrow\quad f = \sin(u)
- 3\frac{df}{dx} = \cos(u)
- 4\frac{df}{dx} = \cos(x^2)
You differentiated sin(u) but stopped there. What does the chain rule say you still owe?
Four keys
It works where you already work
LearnFastAI sits over OneNote, a PDF, Word, or a browser assignment. You never leave your notes to use it.
Check my work
Snip your working. LearnFastAI finds the first line that breaks and names the rule you missed.
Hint my next step
Stuck before you start? Get the governing formula and one strategic move. Not the solution.
Explain this step
Snip a single line from a worked example and get the justification for why it holds.
Ask anything
Not maths working? Ask a plain question — a definition, a history date, an essay prompt — and get a straight answer.
All four keys live in the desktop app.
Download for WindowsA solver knows the answer. It does not know your page.
Type a problem into a solver and you get a final number. It tells you nothing about the four lines you actually wrote, so you still do not know where you went wrong — and in the exam hall you find out you never learned the step you were missing.
LearnFastAI works on your working. It names the line, names the rule, and leaves the last step to you — which is also why it is the kind of tool your course is likely to allow.
A solver says
f′(x) = 2x·cos(x²)
You learn nothing about why yours was wrong.
LearnFastAI says
Line 3 differentiates sin(u) but never accounts for u changing with x.
You find the chain rule yourself, and remember it.
Try it
Real problems, real corrections
These are genuine responses. Pick a problem and a mode.
Your working
Step 3:
Omitted Inner Derivative (Chain Rule)
When differentiating a composite function , you must multiply the derivative of the outer function by the derivative of the inner function .
Hint
What is the derivative of the inner term with respect to ?
The rule
\frac{d}{dx}[f(g(x))] = f'(g(x)) \cdot g'(x)Calculus I · Chain Rule with Composite Polynomials
Before the exam
Your mistakes become a revision list
Every correction is filed by the skill it belongs to. After a few weeks you stop guessing what to revise.
Chain rule on composite functions
Calculus I
Sign convention in kinematics
Mechanics
Integration by parts, second term
Calculus II
Row operations on augmented matrices
Linear Algebra
Your work
Snips are analysed, then discarded
LearnFastAI captures a region only when you press a hotkey. Your snip is sent for analysis and is not stored on our servers afterwards. Desktop history and weak areas stay on your machine.
Pricing
Less than one hour of tutoring
Free
$0
No card required
- 3 checks a day, 30 a month
- All three modes
- Basic weak-area list
- 7 days of history
Pro
$48/year
Works out at $4.00 a month
- 300 checks a month
- Full weak-area analytics and trends
- Unlimited history
- Markdown export for revision
Questions
Reasonable objections
- It is designed as a checker, not an answer generator. In Check and Hint modes the model is instructed to identify the first broken line and offer a next-step hint without completing the problem. AI can still make mistakes, so treat the response as tutoring guidance and keep doing the work yourself.
The app
Put it on the machine you study on
The browser checker works. The overlay is the one you will still be using in week nine: three keys over your own notes, no tab switching, nothing re-typed.
Windows 10 & 11 · Free · No card required