This is a question I've been asked to do and I honestly have no idea how to approach this. Help please?:)
I am purposefully not going though all the steps required to solve the exercise (comment if you need more help).
You might want to have a look at pumping lemma for regular languages .
It gives you a property that all regular languages must satisfy. If you want to show that a language $L$ is not regular, you can show that this property cannot hold. In practice, the proof usually follows these steps:
- assume towards a contradiction that $L$ is regular
- choose a suitable word $w \in L$
- apply the pumping lemma on $w$ to conclude that a new word $w'$ must belong to $L$
- Use the language definition to show that $w'$ does not belong to $L$ (hence the contradiction).
Here is a string $w$ that belongs to your language: $a^n b^n$, for a sufficiently large integer $n>0$.