How to add fractions easilly
Subject:
Trigonometry [1]
My Pre-Cal teacher taught us this. When you are trying to add fractions during a sine or cosine problem, or something that has to do with a unit circle or a triangle, use this:
Ex: 1/4 + 3/5
Multiply 5*1, multiply 4*3 and add them for the numberator, and multiply 4*5 for the denominator.
So it would be 5+12/20. 17/20.
You multiply the denominator of one and numerator of other by the denominator of other and numerator of one.Then add. That will give you the numerator. Then the denomnator you multiply both denominators and add.