A)y'=(9sinx+cosx*tgx)'=9cosx+(cosx)'*tg(x)+cos(x)*(tgx)'=9cosx-sinx*tgx+cosx/cos^2(x)=(9cos^2(x)-sin^2(x)+1)/cosx=(9cos^2(x)-sin^2(x)+sin^2(x)+cos^2(x))/cosx
=10cos^2(x)/cos(x)=10cos(x)
Б)y'=(ctgx/tgx)'=((ctg(x)'*tgx-ctgx*(tgx)')/(tgx)^2=(-1/sin^2(x) * tgx - ctgx*(1/cos^2(x)))/(tgx)^2=(-1/(sinx*cosx)-1/
(sinx*cosx))/(sinx/cosx)^2=-2/(sinx*cosx) * (cosx/sinx)^2=-2cosx/(sin(x)^3
2)Y'=(sin(x^5-8x^3+5x))'=(x^5-8x^3+5x)'*cos(x^5-8x^3+5x)=(5x^4-24x^2+5)*cos(x^5-8x^3+5x)