Version 19 DHS 6.2

DHS - 6.2
Find y´ and y. "
No. 1.19. xy - 6 = cozy.
Find y´ and y. "
No. 2.19. {x = sin2t; y = cos²t.
No. 3.19. For a given function y and argument x0, calculate y ‴ (x0); y = cos²x; x0 = π / 4.
No. 4.19. Write the formula for the derivative of the nth order for the function y = 10ˣ
No. 5.19. Find out at which point of the curve y = x³ / 3 - x² / 2 - 7x + 9; the tangent is the angle with the axis Ox - π / 4.
No. 6.19. The material point moves along the hyperbola xy = 20 so that its abscissa x increases evenly at a speed of 1 m / s.
How fast does the ordinate change when the point passes the position (4; 5)?