Задача 40871.

On the horizontal and vertical deflection plates of the oscilloscope voltage is applied, resulting in a deviation of the electron beam according to the law x (t) = 80cos (25t) (mm) horizontally and y (t) - 20sin (25t) (mm) vertically. Write the equation of the trajectory observed on an oscilloscope screen. To determine the point on the speed of the electron beam on the screen at the time when x = 0.

Detailed solution with a short recording conditions, laws and formulas used in the decision, the withdrawal of the calculation formula and the answer.
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