WolframAlpha

Wolfram|Alpha is a computational knowledge engine that answers questions and calculations entered in natural language or math notation. It draws on curated data and algorithms built on the Wolfram Language, and returns computed results with visual output across mathematics, science, engineering, finance, nutrition, history, linguistics and everyday life topics. The service is aimed at students, teachers, researchers, engineers and general users who need verified computation rather than generated text. The Pro tiers add step by step solutions for problems in math, chemistry and physics, practice problems with hints, guided calculators, upload of data and images for analysis, file downloads, extended computation time and priority support. Pro Premium adds the largest computation allowance and file size limits, and Pro features are also available in the iOS and Android apps. A basic account with sign in is free and does not include step by step solutions. Pro is listed at $5.00 per month billed $60.00 annually, or $9.99 per month on monthly billing. Pro Premium is listed at $8.25 per month billed $99.00 annually, or $12.00 per month on monthly billing. Separate Pro for Students and Pro for Educators plans are also offered. The vendor is part of Wolfram, which also publishes Mathematica and the Wolfram Language.