In a population of cats, the allele for long tails (L) is dominant over the allele for short tails (l). If the frequency of the dominant allele (L) is 0.7, what is the expected frequency of cats with long tails in the population, assuming Hardy-Weinberg equilibrium?

Recall the Hardy-Weinberg principle, which states that allele and genotype frequencies in a population remain constant from generation to generation in the absence of evolutionary influences. The genotype frequencies can be expressed as $p^2$ for homozygous dominant (LL), $2pq$ for heterozygous (Ll), and $q^2$ for homozygous recessive (ll).