###### Exercise6

This exercise asks you to construct some matrices whose columns span a given set.

1. Construct a $$3\times3$$ matrix whose columns span $$\real^3\text{.}$$

2. Construct a $$3\times3$$ matrix whose columns span a plane in $$\real^3\text{.}$$

3. Construct a $$3\times3$$ matrix whose columns span a line in $$\real^3\text{.}$$

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