Determinants Kya Hai? Easy Whiteboard Explanation

Full transcript

Hi friends! Today we are going to learn the topic Determinants. First, let's see what a determinant is. Friends, a determinant is a numerical value calculated from a square matrix. A square matrix has an equal number of rows and columns. Let's understand this with an example, where we draw a small square matrix with two rows and two columns. Friends, let's learn how to calculate a two-by-two determinant. Multiply the elements of the main diagonal, then multiply the other diagonal, and finally subtract the second product from the first product. This gives us the formula: first diagonal product minus the other diagonal product. Friends, now let's solve a three-by-three determinant step by step. We will expand along the first row, so let's carefully draw this bigger square matrix with three rows and three columns. First, take the first element and multiply it by the determinant formed by the remaining rows and columns. Then subtract the second element multiplied by its corresponding minor, and finally add the third element multiplied by its corresponding minor. Now friends, let's calculate each bracket separately, then multiply each result step by step. We subtract and add carefully, keeping every negative sign visible, until we reach our final combined value. So friends, our final answer is minus eighty-six. Remember the two-by-two determinant formula: ad minus bc. In a three-by-three determinant, expand carefully and pay attention to the signs. Practise more examples to improve your understanding. Thank you, friends!