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For example, we know that the sine of the angle at the origin on your graph board is4/5. From that, we can determine the value of the angle. However, we probably can't do this calculation in our heads so we will use the Google calculator to computethe value of the angle.

The arcsine of an angle -- sample computation

Enter the following into the Google search box:

arcsin(4/5) in degrees

The following will appear immediately below the search box:

arcsin(4/5) = 53.1301024 degrees

This is the angle that corresponds to a ratio of the opposite side to the hypotenuse of 4/5.

We can also write a JavaScript script to perform the calculation, which we will do shortly.

Getting the angle for a known sine value

Please use your protractor to measure and record the angle at the origin on your graph board, or measure it on your tactile graphic. Then create an html file containing the code shown in Listing 2 and open it in your browser.

Listing 2 . Arcsin of 3-4-5 triangle.
<!-- File JavaScript02.html --><html><body><script language="JavaScript1.3">function toRadians(degrees){ return degrees*Math.PI/180}//end function toRadians //============================================//function toDegrees(radians){ return radians*180/Math.PI}//end function toDegrees //============================================//var opp = 4 var hyp = 5var ratio = opp/hyp var angRad = Math.asin(ratio)var angDeg = toDegrees(angRad) document.write("radians = " + angRad + "</br>") document.write("degrees = " + angDeg)</script></body></html>

The output for the angle

When you open your html file in your browser, the output shown in Figure 5 should appear in the browser window.

Figure 5 . Output for script in Listing 2.
radians = 0.9272952180016123 degrees = 53.13010235415598

Did you measure the angle to be 53 degrees with your protractor. If so, congratulations. If not, you should probably take another look at it.

Define conversion functions

The code in Listing 2 begins by defining the functions named toRadians and toDegrees that we developed earlier in Listing 1 . (In this case, we will only need the function named toDegrees so I could have omitted the code for the function named toRadians .)

Declare and initialize variables

Then the code in Listing 2 declares and initializes variables to represent the lengths of the opposite side and the hypotenuse for thetriangle on your graph board ( opp and hyp ). Then it computes and saves the ratio of the two. (We learned earlier thatthe ratio is the value of the sine of the angle at the origin even though we don't know the value of the angle.)

The built-in Math.asin method

JavaScript has a built-in method named Math.asin that receives the sine value for an unknown angle and returns the value of thecorresponding angle in radians. (The Math.asin method has the same purpose at the word arcsin in the Google calculator.)

The returned value is an angle between -PI/2 and PI/2 radians. (I will have more to say about this later.)

Listing 2 calls the Math.asin method, passing the ratio (sine of the angle) as a parameter, and stores the returned value in a variablenamed angRad .

Questions & Answers

How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Contemporary math applications. OpenStax CNX. Dec 15, 2014 Download for free at http://legacy.cnx.org/content/col11559/1.6
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