When is a matrix invertible?

A. जब determinant zero न हो / When determinant is not zero

Step 1: Identify the concept: this is inverse matrix condition. Step 2: A square matrix is invertible when its determinant is non zero. Step 3: Remember non zero determinant means inverse exists.

Step 1: concept पहचानें: यह inverse matrix condition है। Step 2: Square matrix invertible तब होती है जब उसका determinant non zero हो। Step 3: Non zero determinant means inverse exists याद रखें।