What if you didn't have to memorise yur formulars ,being it in maths ,physics ,chemistry,etc.Here is a way I was taught to keep my formulars in mind .
In maths for example ,you could try to understand how they are being derived instead .Here is what am talking about ⬇️
The above circle is drawn, showing the arc lenghth represented by the red dotted arrow and the letter l in red .What if asked in exam the formular to find the arc length of a circle and you forget the formular because it is too long or there were too many formulars to memorise .Well , a fraction system will do
Compare two fractions and relate them with the equal sign ,cross multiply and make what you need subject and the deal is done.⬇️
You see ,step 1 shows the comparison of two fractions and step2 the cross multiplication and answer.You could do same for area of sector . So which one is more fun 1or2