Free graphing calculator app for iproducts:
https://itunes.apple.com/us/app/free-graphing-calculator/id378009553?mt=8
Free graphing online: https://www.desmos.com/calculator
https://itunes.apple.com/us/app/free-graphing-calculator/id378009553?mt=8
Free graphing online: https://www.desmos.com/calculator