Matrix, Find determinant using properties of Det.

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The discussion focuses on finding the determinant of a specific 3x3 matrix using properties of determinants. The matrix is transformed by subtracting the first column from the second and third columns, simplifying the determinant calculation. The final determinant expression is derived as (b-a)(c-a)(c-b). The solution confirms that the properties of determinants effectively lead to the correct result. The participant expresses gratitude for the assistance received during the problem-solving process.
am_knightmare
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Homework Statement


1 1 1
a b c = (b-a)(c-a)(c-b)
a^2 b^2 c^2
(above is a 3x3 matrix equaling to a equation)
question:"Show by applying property of the determinant"

Homework Equations


N/A

The Attempt at a Solution


read through the whole chapter of determinants, there were no similar problems. read it the second time focusing on properties, no simimlar properties, Please help.
 
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Start by subtracting the first column from the second and third columns. Then think about an expansion by minors.
 
Just solved it. thanks for the reply though.
1 1 1
a b c
a^2 b^2 c^2
becomes
1 0 0
a b-a c-a
a^2 (b^2-a^2) (c^2-a^2)
then becomes
(b-a)(c-a) times
1 0 0
a 1 1
a^2 b-a c-a
then
1 0 0
a 1 0
a^2 b-a c-b
det= 1 x 1 x(c-b) ( c-a) (b-a)
 
am_knightmare said:
Just solved it. thanks for the reply though.
1 1 1
a b c
a^2 b^2 c^2
becomes
1 0 0
a b-a c-a
a^2 (b^2-a^2) (c^2-a^2)
then becomes
(b-a)(c-a) times
1 0 0
a 1 1
a^2 b-a c-a
then
1 0 0
a 1 0
a^2 b-a c-b
det= 1 x 1 x(c-b) ( c-a) (b-a)

Yup. That'll do it.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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