1 votes 1 votes After taking |A|=0, I am getting x3+1=0 and not x3-1=0. Is it x3+1=0 or x3-1=0? Mathematical Logic ace-test-series test-series engineering-mathematics linear-algebra + – Purple asked Jan 7, 2017 Purple 430 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 1 votes 1 votes |A| = x * ( x*x - 0 ) - (-1)(0 - (-1)(-1)) = 0 [expanding along the first row and |A| should be 0] => $x^3 - 1$ = 0 => x = 1 Pratyush Madhukar answered Jan 7, 2017 • selected Jan 7, 2017 by Purple Pratyush Madhukar comment Share Follow See all 2 Comments See all 2 2 Comments reply Purple commented Jan 7, 2017 reply Follow Share Ya, i missed the '-' in multiplying 2nd parameter. BTW, expansion of (x3-1) is (x-1)(x2+x+1), so x=1, and not -1, for real values of x. 0 votes 0 votes Pratyush Madhukar commented Jan 7, 2017 reply Follow Share Oh, sorry, that's a typo :P editing the answer. 0 votes 0 votes Please log in or register to add a comment.