I am trying to solve this, but I am stuck.... 1 2 -1 2 3 c 0 c -15 1 2 -1 0 -1 (2+c) 0 c -15 1 2 -1 0 1 (-2)-c)) 0 1/15c 1
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Originally Posted by mathproblems I am trying to solve this, but I am stuck.... 1 2 -1 2 3 c 0 c -15 Expand and solve for
Thank you am I doing it correctly? -45-c^2 - 2 (-30 - (-1) -c)) = 0 what shall I do next?
Your expansion of the second det is incorrect. -45 - c^2 -2(-30 +c) = 0 Solve this quadratic equation to get the values of c. (c should be -5 and 3)
Hello, mathproblems! Your method should work if you know what to look for. (But from your responses, I'm not sure you do.) We have: . A matrix is not invertible if an entire row is composed of zeros. That is: . Therefore: .
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