Entering arrays is not working

[Papa Jonah]

I have a spreadsheet that uses an array.
To try and learn how to enter an array, I have retyped it in other cells,
but I can not get it to do anything.
The formula in my template is {=linest(b3:b151,a3:a151,true,true)}. This is
in cells F7:G11.
When I re type it in cell J9, it appears as text instead of actually doing
something.

 

[Dave Breitenbach]

the brackets are not typed - they appear by hitting ctrl alt enter instead of
just enter after typing the formula

 

[Frank Kabel]

Hi
is this cell formated as 'Text'. If yes change the format to 'General'
and re-enter the formula