description of lactation curve were investigated using sine function, compare it with two functions (dijekstra and wood). the data contained 32233 dairy milk yield records from 93 first parity iranian holstein cows that had calving between aug. 2008 and jul. 2009. actual milk production per day and subsequently the actual production of each animal were available in the first lactation. lactatio...

in this paper. (1) we determine the complex-valued solutions of the following variant of van vleck's functional equation $$int_{s}f(sigma(y)xt)dmu(t)-int_{s}f(xyt)dmu(t) = 2f(x)f(y), ;x,yin s,$$ where $s$ is a semigroup, $sigma$ is an involutive morphism of $s$, and $mu$ is a complex measure that is linear combinations of dirac measures $(delta_{z_{i}})_{iin i}$, such that for all $iin i$,...

Using the power series expansion technique, this paper established two new inequalities for sine function and tangent bounded by functions x2sin(λx)/(λx)α x2tan(μx)/(μx)β. These results are better than ones in previous literature.