9xˇ2-xˇ6=xˇ2(9-xˇ4)=xˇ2 (3+xˇ2)(3-xˇ2)=...........xˇ2(3+xˇ2)(V(3)+x)(V(3)-x)
5)А
=1/2[cos(x+x/2) +cos(x-x/2)]-1/2[cos(x-x/2)-cos(x+x/2]
=1/2[cos(x+x/2) +cos(x-x/2)-cos(x-x/2)+cos(x+x/2)]
=1/2[2cos(x+x/2)]
=cos 3x/2
350/(48,5-(48,5*0,24))=350/(48,5-11,64)=350/36,86=9,49