eyeball. 1  Photoreceptors are the cells in the retina that respond to light. Their distinguishing feature is the presence of large amounts of tightly packed membrane that contains the photopigment rhodopsin or a related molecule.
In chemical analysis,  matrix refers to the components of a sample other than the analyte of interest. The matrix can have a considerable effect on the way the analysis is conducted and the quality of the results obtained; such effects are called matrix effects. For example, the ionic strength of the solution can have an effect on the activity coefficients of the analytes.
The coefficient matrix is a matrix comprised of the coefficients of the variables. which is written such that each row represents one equation and each column contains the. coefficients for the same variable in each equation. The constant matrix is the solution to each of the. equations written in a single column and in the same order as the rows of the coefficient matrix. The augmented matrix is the coefficient matrix with the constant matrix as the last column.