For dividing fractions it's also useful to know that the first fraction (1/4) is called the dividend and the second fraction (3/4) is called the divisor.
Let's set up 1/4 and 3/4 side by side so they are easier to see:
1/4 / 3/4
When we find the reciprocal, we also have to change the division sign to a multiplication sign:
1/4 x 4/3
Once you've flipped the second fraction and changed the symbol from divide to multiply, we can multiply the numerators together and the denominators together and we have our solution:
1 x 4 / 4 x 3 = 4/12
Here's a little bonus calculation for you to easily work out the decimal format of the fraction we calculated. All you need to do is divide the numerator by the denominator and you can convert any fraction to decimal:
4/12 = 0.3333