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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

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
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
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
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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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