Trapezoidal rule (approximation for definite integral)
Cellatron R43SM - the ultimate calculator. One of the topmost models across various producers. Also one of the last models of mechanical calculators ever
The rest of the Youtube chanel.
Warning. Did you try the problem by yourself first? Blind rewriting problem to computer and puting down the answer may have serious negative influence on your education. The optimal way how to use this application is to solve the problem and then check your result against computer generated answer.