Find the projection of the vector ` hat i- hat j`on the vector ` hat i+ hat j`

Explanation

To find the projection of the vector \(\hat{i} - \hat{j}\) on the vector \(\hat{i} + \hat{j}\), we will follow these steps:

### Step 1: Define the vectors
Let:
\[ \mathbf{a} = \hat{i} - \hat{j} \]
\[
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