PrismaMath

Fig. 01 · x + y + z = 1 ∩ x − y + z = 0

Maths that is checked, not just explained.

Step-by-step maths lessons on a 2D and 3D board, every result checked by a computer algebra system.

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  • 2D and 3Da board you rotate, zoom and build step by step
  • CASchecks every result on the server before you see it
  • 3 to 5steps per lesson, usually, each tied to the board

§ 01A lesson, step by step

This is what a real lesson looks like.

This is a real lesson, shortened: a student's question about a tangent line. Scroll down and watch the board build with each step.

“What is the tangent to y = sin x at x = π/4?”

23−11 xy y = sin x π/4 √2/2 1 m = √2/2 local approximation P

  1. Step 1 of 4

    Find the curve and the point

    Not just any line: it has to touch the curve at x = π/4. For the full point we also need its height: sin(π/4) = √2/2.

    CASsubst(sin(x), x=pi/4)√2/2✓ checked

  2. Step 2 of 4

    The slope comes from the derivative

    The tangent has the same steepness as the curve at P. Since f′(x) = cos x, the slope is cos(π/4) = √2/2. Common mistake: using sin(π/4), which is the height, not the steepness.

    CASsubst(diff(sin(x),x), x=pi/4)√2/2✓ checked

  3. Step 3 of 4

    Build the line

    With the point and the slope, the point-slope form gives the line: y = √2/2 + √2/2 · (x − π/4).

    CASy = subst(sin(x),x=pi/4) + subst(diff(sin(x),x),x=pi/4)·(x−pi/4)√2/2 + √2/2·(x − π/4)✓ checked

  4. Step 4 of 4

    What tangent means

    The line touches the curve at P and shares its slope right there. It does not match sin x everywhere: it approximates it near the point. That is the idea of the derivative.

Steps shortened from a lesson PrismaMath generated on 26 September 2026 (in Spanish).

Every lesson works like this: explained step by step, drawn and checked.

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§ 02The difference

The language model explains. The CAS does the maths.

A computer algebra system (CAS) does the maths. Every result in a lesson goes through it on the server. If something cannot be checked, the answer is marked unverified or withheld; it is never presented as verified.

  1. QuestionSlope of sin x at x = π/4?
  2. CAS querysubst(diff(sin(x),x), x=pi/4)
  3. Result√2/2
  4. Checked · CAS

§ 03The study room

The explanation on one side, the board on the other.

You move through the steps with “Next” and “Previous”, rotate and zoom the figure, and ask about the step you are on. Your lessons stay in your notebook. Light and dark mode, on your phone too.

The PrismaMath study room with a 3D lesson on where two planes meet
Fig. 02 A real lesson in the study room: two planes and the line where they meet.

§ 04Topics

Built for final-year school maths and first-year university science.

Some topics we have already tried with real questions:

  • 01Tangent lines and derivatives
  • 02Definite integrals as area
  • 03Asymptotes and continuity
  • 04Planes and normal vectors
  • 05Where two planes meet
  • 06Surfaces in 3D
  • 07Ellipses and their foci
  • 08Cross product
  • 09Vector fields
  • 10The exponential and its derivative

Useful for calculus and linear algebra courses and exam preparation.

§ 05Price

One plan, no surprises.

€12/ month

120 answers a month, every result checked by the CAS. Answers that fail or that you cancel do not count.

Launch price, to be confirmed.

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§ 06For teachers and schools

Inside your Moodle, with no student names or emails.

PrismaMath works with Moodle through LTI 1.3: a teacher adds a topic to their course and students open it with a starter question. We do not ask for student names or emails, and it is for formative use: it does not grade.

How it works in a school →

Understand the why, not just the result.

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