Thank you, I understood how Null works )))

I can not pass the PHP test - get error "Failed asserting that false matches expected true".
The square root of 36100 is 190. But there is no such value in the first array.
Array
(
[0] => 121
[1] => 144
[2] => 19
[3] => 161
[4] => 19
[5] => 144
[6] => 19
[7] => 11
)

Array
(
[0] => 121
[1] => 14641
[2] => 20736
[3] => 36100
[4] => 25921
[5] => 361
[6] => 20736
[7] => 361
)