100 баллов Найти частные производные первого и второго порядка

z`(x)=3x²/cos²(x³+y²) z`(y)=2y/cos²(x³+y²) z``(xx)=[6x*cos²(x³+y²)+3x²*2cos(x³+y²)*sin(x³+y²)*3x²]/cos^4(x³+y²)= =[6x*cos²(x³+y²)+9x^4sin(2x³+2y²)]/cos^4(x³+y²) z``(xy)=[3x²*2cos(x³+y²)*sin(x²)*2y]/cos^4(x³+y²)= =6x²y*sin(2x³+2y²)/cos^4(x³+y²) z``(yx)=[2y*2cos(x³+y²)*sin(x³+y²)*2y]/cos^4(x³+y²)= =2y²*sin(2x³+2y²)/cos^4(x³+y²) z``(yy)=[2cos²(x³+y²)+2y*2cos(x³+y²)*sin(x³+y²)*2y]/cos^4(x³+y²)= =[2cos²(x³+y²)+4y²*sin(2x³+2y²)]/cos^4(x³+y²)