Answer:
√m^4 + n^4 +2m²n²
Explanation:
Given the following
Opposite= m²-n²
adjacent = 2mn
Using pythagoras theorem
hyp² = (m²-n²)²+(2mn)²
hyp² = m^4-2m²n²+n^4+4m²n²
hyp² = m^4 + n^4 +2m²n²
hyp = √m^4 + n^4 +2m²n²
hence the required expression is √m^4 + n^4 +2m²n²