To make everything bigger, use \displaystyle in your math tags before writing your code. E.g. \displaystyle \int_a^b{f(x)\,dx} = F(b) - F(a) gives .

To write a fraction, use \frac{}{}, with the numerator in the first set of curly brackets and the denominator in the second. E.g. \frac{\pi}{4} gives .

To input the degree sign, use ^{\circ}, e.g. 30^{\circ} gives .

The square root sign is given by \sqrt{}, write everything you want under it inside the curly brackets. E.g. \sqrt{b^2 - 4ac} gives .