How can we help?
Below you'll find answers to the most common questions. If yours isn't there, write to us directly — we reply personally, usually within a few business days.
Direct contact
info@qorvano.comPlease mention device model, OS version and a short description. Screenshots help for visual questions.
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FAQ
Frequently asked.
Answers to the topics that reach us most often.
How do I restore a purchase?
Open Numeris, switch to the Graphing mode and tap "Restore purchases". The app will then check your Apple or Google account for a previous purchase and unlock the mode automatically.
How do I clear my calculation history?
Open the history panel and tap "Clear all". History is stored strictly locally — there is nothing in the cloud that would need to be deleted as well.
Which mathematical functions are supported?
Arithmetic, roots, powers, logarithms (ln, log), the exponential function (exp), trigonometry (sin, cos, tan and their inverses), absolute value (abs), factorial, symbolic derivatives up to the 5th order, 2D function plots, 3D surfaces as well as the common mathematical constants (π, e, i).
Why doesn't the app recognise my formula?
Check that all bracket pairs are closed (the app highlights them in colour). Implicit multiplication is supported — "2x" is interpreted as "2*x". Trigonometric functions expect parentheses around their argument: sin(x), not sin x.
Can I use Numeris in portrait and landscape?
Yes. Numeris is designed for both orientations. On iPad and Android tablets you get a wider keypad and expression view in landscape.
Is Numeris available in my language?
Numeris is available in 20 languages. The app adopts your device's system language automatically. Supported languages include German, English, French, Spanish, Italian, Portuguese, Japanese, Korean, Chinese, Russian, Turkish, Arabic, Hindi, Dutch, Polish, Swedish, Danish, Norwegian, Finnish and Ukrainian.
Why isn't there a dark/light toggle?
Numeris follows the system setting. When you choose light or dark mode in your iOS/Android settings, Numeris adapts. This keeps the appearance consistent with the rest of the operating system.
Is any data sent to Qorvano° or third parties?
No. Numeris collects, stores and transmits no personal data. Purchases are processed exclusively by Apple or Google. Details are in the privacy policy.
Your question isn't listed?
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