# Previous answers holtlinalg1 51034 find all real

• Homework Help
• 16
• 100% (90) 90 out of 90 people found this document helpful

This preview shows page 4 - 8 out of 16 pages.

3/3 points | Previous Answers HoltLinAlg1 5.1.034. Find all real values of a such that the given matrix is not invertible. (HINT: Think determinants, not row operations. Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) a 6 1 a a R . a R . Solution or Explanation or A is not invertible if or A = a 6 1 a a = \$\$DNE det = a 2 + 6 = 0 A = 0 4 a a 1 5 0 a 1 a = \$\$0, 2,2 det = a 3 4 a = a ( a 2 )( a + 2 ) = 0 0 4 a a 1 5 0 a 1 a = 0, a = 2 , a = 2 . a = 0, a = 2 , a = 2 .
6. 2/2 points | Previous Answers HoltLinAlg1 5.1.035. Find det( A ). No cofactor expansions are required. -12 -12 Explain your answer. A = 4 0 0 0 26 1 0 0 20 16 1 0 9 25 19 3 ,
7. 2/2 points | Previous Answers HoltLinAlg1 5.1.037. Find det( A ). No cofactor expansions are required. 0 Explain your answer. A = 2 3 0 5 0 6 0 9 3 0 0 2 2 3 0 1 0
8. 2/2 points | Previous Answers HoltLinAlg1 5.1.039. Find det( A ). No cofactor expansions are required.