Answer:
001*|1*00
Explanation:
The language consists of strings in {0,1} that either start with 00 or end with 00 and have no more zeros.
The requirement can be divided into two parts:
1) Strings that start with 00 and have no more zeros
2) Strings that end with 00 and have no more zeros
Generating regular expressions for these parts:
1) 001* - starts with two zeros and can have zero or more 1s later
2)1*00 - starts with zero or more 1s and ends with two zeros
So on combining with the or operator(|), the overall regular expression for the strings in the language becomes:
001*|1*00
