This is an advanced scientific calculator that can be used online. Enter the expressions you want to calculate in the same order you would write them on paper. For example, if you want to calculate the cosine of 0.5, press the cos button, then write 0.5, then press the '=' button.
Use your keyboard (click here for a list of keyboard shortcuts) or use your mouse to click on the keys. The expression appears in the upper display as you type it. The result is calculated and displayed after pressing '='.
Click here for the instruction manual