Please make the question more specific. Do you know the frequency of the sine function you want to extract? Or would you like to find it out? In general you can try to fit your function f(t) as:

f(t) = C0 + C1 * cos(2*pi*w*t) + C2 * sin(2*pi*w*t).

Then you task is to identify the parameters. C0, C1, C2. You can find W by analyzing the spectrum of f(t). There are numerous methods that can do. Particular method depends on the spectral properties of f. If it has many peaks and you are interested in the first one, you might use Welch method. If instead it has just one harmonics, covariance method may do better as it represents f(t) as an output of a dynamic system (AR-model) and you can explicitly set the order of the system.

Thanks all for valuable answers..

basically I am searching for a lab/experimental setup, that help me to represent all hormonics

(sinosoidal), for an example,if I provide a traingular wave at input, which i can see at CRO,

then that setup provide me all harmonics at output terminal CRO.

ahaa.. i got a solution, We have kit of spectrum analyser (provide frequency v/s magnitude response), from which we can see the different harmonic component s of a periodic wave, If we pass a sine wave of particular frequency, then we get the a single peak of the particular frequency, If we pass a triangular wave, then we get the different- different peaks, and we can filtered out any peak,mans sinusoidal wave of a particular frequency. ... I thinks, circuitry inside the analyser, is the solution to find or separate out the different harmonics,,,

Suggest me if any other technique is available...

Only a Non Sinusoidal Periodic wave satisfying the Dirichlet Conditions(having a finite number of discontinuities,possessing a finite number of Maxima and Minima and being absolutely Convergent) can be represented by Fourier Series.

In the Fourier Series the Constant or Average Value may be present or may not be if the wave does not have a D.C. Component.

Depending on the condition whether the function is an odd function in which case it will have only Sine Components or even function in which case only Cosine Components will be present.

Depending on Half wave Symmetry if it is present, only Odd Harmonics will be present and so on. Please refer http://www.ece.rutgers.edu/~psannuti/ece224/PEEII-Expt-6-07.pdf

As it is a series We can ignore the remaining Harmonics depending on the accuracy we need for the value of the function at any time t.

From Fourier Series in Trigonometric form we can go to Fourier Series in Exponential Form and from there we can go to derive Fourier Transforms for Non Periodic function and from there Laplace Transforms.

From Laplace Transforms we can obtain Steady State response for Sinusoidal Excitation of a Circuit. By substituting s = jw in the transform Indutance Z(s) = sL, we get impedance of the Inductance,Xl = jwL.

P.S.

Fourier Transform may yield tha answer but the accuracy will not be correct as i have tested this as it was related to my theis so just use wavelet Transform technique and arrange them in desending order form a system of equation and solve it ..u will get the required ...