w=∇×u Is this correct? w_i=ε_ijk ∂/(∂x_j ) u_k

w and u are the vectors

C=(x∙y)z Is this correct? C_i= ∑_i〖(x_i y_j)∙z_i 〗

C, x, y, z are vectors

A^T∙A ∙x=A^T∙b Is this correct? A_ij^T∙A_ij∙x_j=A_ij^T∙b_i

A is tensor and x and b are vectors

A^T is A transpose