У вашего броузера проблема в совместимости с HTML5
Finding the equation for a tangent line or a secant line is the exact same process, with ONE difference. When you go to find the slope of a secant line, you use the slope formula. When you go to find the slope of a tangent line, you use the derivative. Everything else is the same! Also, sorry for the terrible handwriting. I forgot to take my tablet thing home over the weekend.