The following models of CASIO calculator may work with this method: fx-570ES, fx-570ES Plus, fx-115ES, fx-115ES Plus, fx-991ES, and fx-991ES Plus.
 

The following calculator keys will be used for the solution

Name Key Operation Shift SHIFT Mode MODE

Name Key Operation Stat SHIFT → 1[STAT] AC AC

This is one of the series of post in calculator techniques in solving problems. You maybe interested also on my previous post in calculator technique for progression problems and calculator technique for clock problems; both in Algebra.
 

The following models of CASIO calculator may work with these methods: fx-570ES, fx-570ES Plus, fx-115ES, fx-115ES Plus, fx-991ES, and fx-991ES Plus.
 

Before we go to Calculator technique, let us first understand the movements of the hands of our continuously driven clock.
 

For simplicity, let "dial" be the unit of one hand movement and there are 60 dials in the complete circle as shown in the figure.
 

This is the first round for series of posts about optimizing the use of calculator in solving math problems. The calculator techniques I am presenting here has been known to many students who are about to take the engineering board exam. Using it will save you plenty of time and use that time in analyzing more complex problems. The following models of CASIO calculator may work with these methods: fx-570ES, fx-570ES Plus, fx-115ES, fx-115ES Plus, fx-991ES, and fx-991ES Plus.
 

Any one who took an engineering board examination will agree with me that scientific calculator is our best friend during the examination. It will speed up our work and will allow us to go through the analysis of the problem. In most cases, solving the equation is not the real issue, it is to write the correct equation that matters. If we are able to determine the correct equation of a particular situation, the burden of that problem is over. Our next step is obviously to solve for the desired value. It is important to note that the correct answer can only be derived from the correct equation. To determine the correct equation is where should our brain go, not in finding the solution of that equation. You guess it right, we use our best friend, the scientific calculator, to do the task. Don't do manual calculation please, the examiner will not give you bonus points in finding the roots of
 

manually. Calculator can easily solve for the value of θ fast and accurate than you.