This paper presents the Theory of relativity and its coupling with quantum physics using the equations set by Einstein, Planck, and de Broglie. Using the Lorentz factor, known as the cosine function, we construct a graph that fully correspond to Einstein's Theory of relativity and relates it to quantum physics. This connection is made using a sine rule via Planck equation and results in de Brogli wavelength. In this way, the known fact of the cosine rule for Einstein's theory is simply and elegantly extended by applying the sine function. What we get is fascinating - the merging of sines and cosines on the same basis unites quantum and relativistic physics. Thus, when changing the velocity variable in the range from zero to the speed of light, the required energy to accelerate the particle follows the theoretical range from zero to infinity, while the radiation energy is limited by the mass of the particle that is accelerated. This paper in a logical, systematic and mathematical way enables us to unite quantum and relativistic physics within one graph on which they are all together: Einstein, Lorentz, Planck and de Broglie.