Trigonometrical functions come not to all school students easily. And if still it is possible to cope with the equations somehow by means of formulas, then to construct the schedule of cos or sin for some it seems an impossible task. Meanwhile, for this purpose it is only necessary to know an algorithm of creation of schedules of trigonometrical functions.

Initial substances (initial), entering interaction, turn into final (products). It is so-called "direct reaction". But in some cases also the return reaction when products turn into initial substances at the same time begins to go. And if the speed of course of direct and return reaction becomes identical, it means that in a system the chemical balance was established. How can it be defined?

In spite of the fact that the word "perimeter" is translated from Greek as "circle", designate by it the total length of all borders not only a circle, but also any convex geometrical figure. One of such flat figures is the triangle. For finding of length of its perimeter it is necessary to know or lengths of three parties, or to use ratios between lengths of the parties and corners in tops of this figure.

In the structure of the planet Earth allocate a kernel, a cloak and bark. A kernel – the central part located most far from a surface. The cloak is located under bark and kernels are higher. At last, bark – an outer firm sheath of the planet.