回答:
#DY / DX = 4cos(1-2倍)SIN(1-2倍)#
说明:
首先,让我们 #cos(1-2倍)= U#
所以, #y的= U ^ 2#
#DY / DX =(DY)/(DU)*(DU)/(DX)#
#(DY)/(DU)= 2U#
#(DU)/(DX)= d / DX COS(1-2倍) = d / DX COS(V)#
#(DU)/(DX)=(DU)/(DV)*(DV)/(DX)#
#dy / dx =(dy)/(du)*(du)/(dv)*(dv)/(dx)#
#(DU)/(DV)= - SIN(v)的#
#(DV)/(DX)= - 2#
#DY / DX = 2U * -sin(v)的* - 2#
#DY / DX = 4usin(V)#
#DY / DX = 4cos(1-2倍)SIN(1-2倍)#