$\"\"$

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(a)

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The points are $\"\"$ , $\"\"$ and $\"\"$ .

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The points that lie on a same line are called collinear points.

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If the three points $\"\"$ and $\"\"$ are collinear if and only if $\"\"$ .

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Consider $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$ .

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$\"\"$ .

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$\"\"$ .

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Therefore, the ponits are does not lies on straight line.

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$\"\"$

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(b)

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The points are $\"\"$ , $\"\"$ and $\"\"$ .

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If the three points $\"\"$ and $\"\"$ are collinear if and only if $\"\"$ .

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Consider $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$ .

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$\"\"$ .

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$\"\"$ .

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Therefore, the ponits lies on straight line.

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$\"\"$

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(a) The ponits are does not lies on straight line.

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(b) The ponits lies on straight line.