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<h2 class="hd hd-2 unit-title">2.3 Session Overview</h2>
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<p>Linear regression is commonly used to fit a line to a collection of data. The method of least squares can be viewed as finding the projection of a vector. Linear algebra provides a powerful and efficient description of linear regression in terms of the matrix <em>A</em><sup>T</sup><em>A</em>.</p>
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<h2 class="hd hd-2 unit-title">Lecture Summary and Reading</h2>
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<h3>Lecture Summary </h3>
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<h3>Suggested Reading</h3>
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<li>Read Section 4.3 in the 4<sup>th</sup> or 5<sup>th</sup> edition. </li>
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<h3 class="hd hd-2">Least Squares Approximation</h3>
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<p>Work the problems on your own and check your answers when you're done.</p>
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