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One possible condition for the three poi...

One possible condition for the three points (a,b), (b,a) and `(a^(2),-b^(2))` to be collinear is

A

`a-b=2`

B

`a+b=2`

C

`a=1+b`

D

`a=1-b`

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The correct Answer is:
To determine one possible condition for the three points \((a,b)\), \((b,a)\), and \((a^2,-b^2)\) to be collinear, we can use the concept of the determinant of a matrix formed by these points. The points are collinear if the determinant of the following matrix is equal to zero: \[ \begin{vmatrix} a & b & 1 \\ b & a & 1 \\ a^2 & -b^2 & 1 \end{vmatrix} = 0 \] ### Step 1: Set up the determinant We start with the determinant: \[ D = \begin{vmatrix} a & b & 1 \\ b & a & 1 \\ a^2 & -b^2 & 1 \end{vmatrix} \] ### Step 2: Expand the determinant Using the formula for the determinant of a 3x3 matrix, we expand it: \[ D = a \begin{vmatrix} a & 1 \\ -b^2 & 1 \end{vmatrix} - b \begin{vmatrix} b & 1 \\ a^2 & 1 \end{vmatrix} + 1 \begin{vmatrix} b & a \\ a^2 & -b^2 \end{vmatrix} \] ### Step 3: Calculate the 2x2 determinants Calculating each of the 2x2 determinants: 1. \(\begin{vmatrix} a & 1 \\ -b^2 & 1 \end{vmatrix} = a \cdot 1 - (-b^2) \cdot 1 = a + b^2\) 2. \(\begin{vmatrix} b & 1 \\ a^2 & 1 \end{vmatrix} = b \cdot 1 - a^2 \cdot 1 = b - a^2\) 3. \(\begin{vmatrix} b & a \\ a^2 & -b^2 \end{vmatrix} = b \cdot (-b^2) - a \cdot a^2 = -b^3 - a^3\) ### Step 4: Substitute back into the determinant Now substituting these back into the expression for \(D\): \[ D = a(a + b^2) - b(b - a^2) + (-b^3 - a^3) \] ### Step 5: Simplify the expression Expanding and simplifying: \[ D = a^2 + ab^2 - (b^2 - ba^2) - b^3 - a^3 \] \[ D = a^2 + ab^2 - b^2 + ba^2 - b^3 - a^3 \] \[ D = (a^2 + ba^2) + (ab^2 - b^2) - b^3 - a^3 \] \[ D = a^2(1 + b) + b^2(a - 1) - b^3 - a^3 \] ### Step 6: Set the determinant to zero Setting \(D = 0\): \[ a^2(1 + b) + b^2(a - 1) - b^3 - a^3 = 0 \] ### Step 7: Factor the expression This can be factored or rearranged to find conditions. One possible condition derived from this equation is: \[ a - b = 0 \quad \text{or} \quad a + b = 0 \quad \text{or} \quad a = 1 + b \] ### Conclusion Thus, one possible condition for the three points to be collinear is: \[ a = 1 + b \]

To determine one possible condition for the three points \((a,b)\), \((b,a)\), and \((a^2,-b^2)\) to be collinear, we can use the concept of the determinant of a matrix formed by these points. The points are collinear if the determinant of the following matrix is equal to zero: \[ \begin{vmatrix} a & b & 1 \\ b & a & 1 \\ a^2 & -b^2 & 1 \end{vmatrix} = 0 ...
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