Answer:
To create the required users with the specified login requirements, you can use SQL commands in an Oracle database. Here's an example of how you can achieve this:
1. Create the users with the necessary privileges and settings:
```sql
-- Create the cust_user user
CREATE USER cust_user IDENTIFIED BY password DEFAULT TABLESPACE tbs_ext TEMPORARY TABLESPACE temp QUOTA UNLIMITED ON tbs_ext;
-- Create the invent_user user
CREATE USER invent_user IDENTIFIED BY password DEFAULT TABLESPACE tbs_ext TEMPORARY TABLESPACE temp QUOTA UNLIMITED ON tbs_ext;
```
In the above commands, we create two users: `cust_user` and `invent_user`. They are both identified by the password "password". The default tablespace is set to `tbs_ext`, and the temporary tablespace is set to `temp`. The `QUOTA UNLIMITED ON tbs_ext` clause ensures that both users have unlimited quota on the `tbs_ext` tablespace.
2. Set the password requirements:
```sql
-- Set the password requirements for cust_user
ALTER USER cust_user PROFILE DEFAULT;
-- Set the password requirements for invent_user
ALTER USER invent_user PROFILE DEFAULT;
```
By using the `ALTER USER` statement with the `PROFILE DEFAULT` clause, we assign the default profile to both users. The default profile includes password policies such as minimum length, password expiration, and password reuse.
3. Force cust_user to change their password on first login:
```sql
-- Force cust_user to change their password on first login
ALTER USER cust_user PASSWORD EXPIRE;
```
The `ALTER USER` statement with the `PASSWORD EXPIRE` clause forces the user `cust_user` to change their password on the next login.
4. Set password expiration and password reuse policies:
```sql
-- Set password expiration and password reuse policies for cust_user
ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME 90 PASSWORD_REUSE_TIME 90 PASSWORD_REUSE_MAX 1;
-- Set password expiration and password reuse policies for invent_user
ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME 90 PASSWORD_REUSE_TIME 90 PASSWORD_REUSE_MAX 1;
```
In the above commands, we set the password expiration to 90 days (`PASSWORD_LIFE_TIME 90`) and the password reuse time to 90 days (`PASSWORD_REUSE_TIME 90`). The `PASSWORD_REUSE_MAX 1` clause ensures that the users are not allowed to reuse the same password.
After executing these SQL commands, you will have created the `cust_user` and `invent_user` users with the specified login requirements. The passwords for the created users are "password" (existing). The users will be prompted to change their passwords on the first login and will be required to change their passwords every three months. They will not be allowed to reuse the same password.
Please note that the screenshots of the successful execution of these SQL commands cannot be provided as this platform only supports text-based responses. However, you can execute these commands in an Oracle database environment to see the successful execution and verify the results.