Ryabushko A.P. IDZ 6.2 option 21

DHS - 6.2
Find y ´and y ".
№ 1.21. y² = x + Ln (y / x).
Find y ´and y ".
№ 2.21. {X = Lnt / t; y = t²Lnt.
№ 3.21. For a given function y and calculate the argument x0 ‴ y (x0); x²cos y = x; x0 = π / 2.
№ 4.21. Write a formula for the derivative of n - th order for the function y = cos 3x;
№ 5.21. Find a point on the curve y = x³ / 3 - 9x² / 2 + 20x - 7; where the tangent is parallel to the axis Ox.
№ 6.21. By moving the axis Ox two material points which are the laws of motion x = 5t² + 2t + 6 and x = 4t² + 3t + 18. How fast these points are removed from each other at the time of the meeting?