Find the angle between the lines `vecr = (hati+hatj)+lambda(3hati+2hatj+6hatk)` and `vecr = (hati-hatk) + mu(hati+2hatj+2hatk)`

Explanation

To find the angle between the two lines given by the vector equations:

1. **Line 1**: \(\vec{r} = \hat{i} + \hat{j} + \lambda(3\hat{i} + 2\hat{j} + 6\hat{k})\)
2. **Line 2**: \(\vec{r} = \hat{i} - \hat{k} + \mu(\hat{i} + 2\hat{j} + 2\hat{k})\)

we need to extract the direction ratios from these equations.

### Step 1: Identify Direction Ratios
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