document.write( "Question 262916: what is the value of the determinant?
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Algebra.Com's Answer #193701 by jim_thompson5910(35256) $\"\"$ $\"About$

You can put this solution on YOUR website!
Take note that two rows are identical. This means that the determinant must be zero. However, let's use another method.\r
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Solved by pluggable solver: Finding the Determinant of a 3x3 Matrix

If you have the general 3x3 matrix:

$\"%28matrix%283%2C3%2Ca%2Cb%2Cc%2Cd%2Ce%2Cf%2Cg%2Ch%2Ci%29%29\"$

the determinant is:

Which further breaks down to:

Note: $\"abs%28matrix%282%2C2%2Ce%2Cf%2Ch%2Ci%29%29\"$ , $\"abs%28matrix%282%2C2%2Cd%2Cf%2Cg%2Ci%29%29\"$ and $\"abs%28matrix%282%2C2%2Cd%2Ce%2Cg%2Ch%29%29\"$ are determinants themselves.
If you need help finding the determinant of 2x2 matrices (which is required to find the determinant of 3x3 matrices), check out this solver

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From the matrix $\"%28matrix%283%2C3%2C3%2C6%2C8%2C2%2C4%2C0%2C3%2C6%2C8%29%29\"$ , we can see that $\"a=3\"$ , $\"b=6\"$ , $\"c=8\"$ , $\"d=2\"$ , $\"e=4\"$ , $\"f=0\"$ , $\"g=3\"$ , $\"h=6\"$ , and $\"i=8\"$

Start with the general 3x3 determinant.

Plug in the given values (see above)

Multiply

Subtract

$\"abs%28matrix%283%2C3%2C3%2C6%2C8%2C2%2C4%2C0%2C3%2C6%2C8%29%29=96-96%2B0\"$ Multiply

$\"abs%28matrix%283%2C3%2C3%2C6%2C8%2C2%2C4%2C0%2C3%2C6%2C8%29%29=0\"$ Combine like terms.

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Answer:

So $\"abs%28matrix%283%2C3%2C3%2C6%2C8%2C2%2C4%2C0%2C3%2C6%2C8%29%29=0\"$ , which means that the determinant of the matrix $\"%28matrix%283%2C3%2C3%2C6%2C8%2C2%2C4%2C0%2C3%2C6%2C8%29%29\"$ is 0

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