07.11.2007, 19:37
общий
это ответ
Здравствуйте, Курилов Олег Олегович!
2) y = x * (cos(ln(x)) + sin(sin(x))).
y‘ = x‘ * (cos(ln(x)) + sin(sin(x))) + x * (cos(ln(x)) + sin(sin(x)))‘ =
cos(ln(x)) + sin(sin(x)) + x * (cos(ln(x))‘ + sin(sin(x))‘) =
cos(ln(x)) + sin(sin(x)) + x * (-sin(ln(x))*(ln(x))‘ + cos(sin(x))*(sin(x))‘) =
cos(ln(x)) + sin(sin(x)) + x * (-sin(ln(x))*1/x + cos(sin(x))*cos(x)) =
cos(ln(x)) + sin(sin(x)) – sin(ln(x)) + x*cos(x)*cos(sin(x)).
3)
y = t/3 – t = -2t/3,
x = t².
dy/dt = -2/3,
dx/dt = 2t,
y‘ = dy/dx = (-2/3)/(2t) = -1/(3t);
d(y‘)/dt = d²y/(dxdt) = 1/(3t²),
y‘‘ = d²y/dx² = (1/(3t²))/(2t) = 1/(6t³).