Where did trig functions come from?

misogynisticfeminist
Messages
370
Reaction score
0
I've been thought trig functions in school definitely, but never been told how were they invented in the first place! Also, is there a function like sin (theta)= something. If so, what are these functions?
 
Mathematics news on Phys.org
"is there a function like sin (theta)= something."

pardon? what do you mean 'like'? or something? sin is a function, it's like itself, it's 'like' a power series, is that what you mean?
 
Check this http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/Trigonometric_functions.html.

-- AI
Another Reference : http://www.math.unifi.it/archimede/archimede_inglese/trigonometria/trigonometria/prima.html but says the same thing.
 
Last edited by a moderator:
  • Like
Likes samg1
thanks the history part was useful.

to matt: actually what i meant was could I get a function while I substitute theta, I will get the result of sine theta without using my calculator to find sine theta of course.
 
Without using a calculator? OF course not. calculate the square of 3.45234232526 without one - takes a while agreed? calculate the square of the 5#th root of 2. this is of course a question about what you mean by calculate. in this case you mean find a decimal representation of. to what degree of accuracy?

there are many ways to caculate sin, cos and many other functions as power series, called taylor or maclaurin series.

\sin(x)= x - \frac{x^3}{3!} + \frac{x^5}{5!}- \frac{x^7}{7!} \ldots

terminate after as many terms as required.
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
Fermat's Last Theorem has long been one of the most famous mathematical problems, and is now one of the most famous theorems. It simply states that the equation $$ a^n+b^n=c^n $$ has no solutions with positive integers if ##n>2.## It was named after Pierre de Fermat (1607-1665). The problem itself stems from the book Arithmetica by Diophantus of Alexandria. It gained popularity because Fermat noted in his copy "Cubum autem in duos cubos, aut quadratoquadratum in duos quadratoquadratos, et...
Thread 'Imaginary Pythagorus'
I posted this in the Lame Math thread, but it's got me thinking. Is there any validity to this? Or is it really just a mathematical trick? Naively, I see that i2 + plus 12 does equal zero2. But does this have a meaning? I know one can treat the imaginary number line as just another axis like the reals, but does that mean this does represent a triangle in the complex plane with a hypotenuse of length zero? Ibix offered a rendering of the diagram using what I assume is matrix* notation...

Similar threads

Replies
5
Views
2K
Replies
14
Views
2K
Replies
17
Views
6K
Replies
5
Views
1K
Replies
2
Views
862
Replies
7
Views
1K
Replies
10
Views
28K
Back
Top