Trigger below will verify any change in one of these fields (which you have entered) and var enter the value of the Tarefaid field in the Tasks table.
Includes a cursor so that if a batch operation is performed, all occurrences are recorded in the Task table.
If any exception occurs, it will be captured and displayed to the user in a custom way. 
Note: I assumed that your Tasks table has the field InstrucaoID as identity;
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[TGR_TAREFA_AU]') AND type in (N'TR'))
    DROP TRIGGER [dbo].[TGR_TAREFA_AU]
GO
CREATE TRIGGER [dbo].[TGR_TAREFA_AU]
ON [dbo].[TAREFA]
WITH ENCRYPTION
AFTER UPDATE
AS
BEGIN
    SET NOCOUNT ON;
    DECLARE @tTarefaID INT
    IF UPDATE(TarefaID) OR UPDATE(Vencimento) OR UPDATE(Status) OR UPDATE(Caminho) OR UPDATE(ModuloID)
    BEGIN
        BEGIN TRAN
        BEGIN TRY
            DECLARE CURSOR_TAREFA CURSOR FOR 
            SELECT TarefaID FROM Inserted INS
            OPEN CURSOR_TAREFA
            FETCH NEXT FROM CURSOR_TAREFA INTO @tTarefaID
            WHILE @@FETCH_STATUS = 0
            BEGIN
                INSERT INTO INSTRUCAO (TarefaID) VALUES(@tTarefaID)
                FETCH NEXT FROM CURSOR_TAREFA INTO @tTarefaID
            END
            CLOSE CURSOR_TAREFA
            DEALLOCATE CURSOR_TAREFA
            COMMIT
        END TRY
        BEGIN CATCH
            IF @@TRANCOUNT > 0 ROLLBACK
            DECLARE @_ERROR_PROCEDURE VARCHAR(MAX)
            SET @_ERROR_PROCEDURE = 'Err Nº: ' + CAST(ERROR_NUMBER() AS VARCHAR(10)) +' | Severidade: '+ CAST(ERROR_SEVERITY() AS VARCHAR(10)) + ' | Estado: ' + CAST(ERROR_STATE() AS VARCHAR(10)) + ' | Procedure: '+ ISNULL(ERROR_PROCEDURE(),'') + ' | Linha: '+ CAST(ERROR_LINE() AS VARCHAR(10)) + ' | Erro: '+ ERROR_MESSAGE()   
            RAISERROR(@_ERROR_PROCEDURE,16,1)           
        END CATCH
    END
END
GO
							
							
						 
The difficulty is in creating the
triggerinsert into the instruction table?– Marconi
the difficulty is to insert in the instruction table any change in any field q I cited in the task table.
– Renan Bessa