Things to mention:
Many films and television programmes[?] have been filmed at London Zoo, the most famous being Harry Potter and the Philosopher's Stone.
... 4a2. We get <math>\left(x+\frac{b}{2a}\right)^2=\frac{-4ac+b^2}{4a^2}=\frac{b^2-4ac}{4a^2}.</math> Taking square roots of bo ...