Is it possible to concatenate the headers lines in a file with the output from a filter using `grep`? Perhaps using the `cat` command or something else from GNU's coreutils?

In particular, I have a tab delimited file that roughly looks like the following:

```
var1   var2   var3
1      MT     500
30     CA     40000
10     NV     1240   
40     TX     500   
30     UT     35000
10     AZ     1405
35     CO     500
15     UT     9000
1      NV     1505
30     CA     40000
10     NV     1240

```

I would like to select from lines 2 - N all lines that contain "CA" using `grep` and also to place the first row, the variable names, in the first line of the output file using GNU/Linux commands.

The desired output for the example would be:

```
var1   var2   var3
30     CA     40000
35     CA     65000
15     CA     2500

```

I can select the two sets of desired output with the following lines of code.

```
head -1 filename
grep -E CA filename

```

My initial idea is to combine the output of these commands using `cat`, but I have not been successful so far.