$$x = {-b \pm \sqrt{b^2-4ac} \over 2a}$$ $$P(Z=z) = {1\over{2\pi}}e^{\frac{1}{2}t^2}$$ $$h = \sqrt{a^2 + b^2}$$ $${{a}\over{\sin A}} = {{b}\over{\sin B}} = {{c}\over{\sin C}}$$ $$A _{\Delta} = \frac{1}{2}ab\sin C$$
$$a^{m} \times a^{n} = a^{m+n}$$ $$a^{m} \div a^{n} = a^{m-n}$$ $$(a^{m})^{n} = a^{mn}$$ $$a^{-m} = {{1}\over{a^{m}}}$$ $$a^{\frac{m}{n}} = \sqrt[n]{a^{m}}$$ $$a^{0} = 1$$