| written 9.5 years ago by | • modified 9.5 years ago |
Let V be a non-zero inner product space in $R^3$ and let u = {$u_{1}$, $u_{2}$, $u_{3}$} be any base for V.
Following are the steps to find orthonormal basis using Gran - Schmidt process:
Let $u_{1} = [1, 2, 0]$ & $u_{2} = [0, 3, 1]$
Step1: $v_{1} = u_{1} = (1, 2, 0)$
Step 2: $v_{2} = u_{2} - proj u_{2} = u_{2} - \frac{\lt u_{2}, v_{1}\gt}{||v_{1}||^2}v_{1}$
Now $\lt u_{2}, v_{1}\gt = (0, 3, 1) * (1, 2, 0) = 6$
$||v_{1}||^2 = 1 + 4 = 5 \\ \therefore v_{2} = (0, 3, 1) - \frac{6}{5}(1, 2, 0) = \bigg(-\frac{6}{5}, \frac{3}{5}, 1 \bigg) \\ ||v_{2}||^2 = \frac{36}{25} + \frac{9}{25} + 1 = \frac{14}{5}$
Hence $v_{1}$ = (1, 2, 0) & $v_{2} = \bigg(-\frac{6}{5}, \frac{3}{5}, 1 \bigg)$ forms orthogonal basis of $R^3$
Now, the norms of these vectors are
$$||v_{1}|| = \sqrt{5} \\ ||v_{2}|| = \sqrt{\frac{14}{5}}$$
Hence orthonormal basis for $R^3$ is
$$q_{1} = \frac{v_{1}}{||v_{1}||} = \bigg(\frac{1}{\sqrt{5}}, \frac{2}{\sqrt{5}}, 0 \bigg) \\ q_{2} = \frac{v_{2}}{||v_{2}||} = \bigg(\frac{-6}{\sqrt{70}}, \frac{3}{\sqrt{70}}, \sqrt{\frac{5}{14}}\bigg)$$

and 3 others joined a min ago.