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July 14th, 2019, 07:12 AM   #1
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I need help

I have two questions, they should be either true or false and I am asked to justify my answer.



Thank you in advance.
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July 14th, 2019, 08:41 AM   #2
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Q1) A square matrix is singular if its determinant is zero (and vice versa). Find the determinant and see whether it equates to zero for all a, b, c.

Q2) If I recall correctly, |AB| is equal to |A||B|. If that's true, then |B| = (|P|/|P|)|A| = |A|.
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Last edited by skipjack; July 14th, 2019 at 08:13 PM.
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July 15th, 2019, 02:32 PM   #3
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Thank you so much for the help!
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July 16th, 2019, 07:37 PM   #4
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Hello, for Q1) My friend had the solution below:


How did he come to this solution? I have tried to calculate the determinant but the unknowns made it a headache for me.
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July 16th, 2019, 08:42 PM   #5
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Quote:
Originally Posted by Canopus View Post
Hello, for Q1) My friend had the solution below:


How did he come to this solution? I have tried to calculate the determinant but the unknowns made it a headache for me.
It's just standard Gaussian elimination

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July 17th, 2019, 03:31 AM   #6
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Thank you Boss!
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