The 2 sets of axes must share the origin. {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} {" "} Ix1x1=Ixx+Iyy2+(Ixx−Iyy2)cos2θ−Ixysin2θI_{x_1x_1} = \frac{I_{xx} + I_{yy}}{2} + \bigg(\frac{I_{xx} - I_{yy}}{2}\bigg)\cos{2\theta} - I_{xy}\sin{2\theta}Ix1x1=2Ixx+Iyy+(2Ixx−Iyy)cos2θ−Ixysin2θ Iy1y1=Ixx+Iyy2−(Ixx−Iyy2)cos2θ+Ixysin2θI_{y_1y_1} = \frac{I_{xx} + I_{yy}}{2} - \bigg(\frac{I_{xx} - I_{yy}}{2}\bigg)\cos{2\theta} + I_{xy}\sin{2\theta}Iy1y1=2Ixx+Iyy−(2Ixx−Iyy)cos2θ+Ixysin2θ Ix1y1=(Ixx−Iyy2)sin2θ+Ixycos2θI_{x_1y_1} = \bigg(\frac{I_{xx} - I_{yy}}{2}\bigg)\sin{2\theta} + I_{xy}\cos{2\theta}Ix1y1=(2Ixx−Iyy)sin2θ+Ixycos2θ
