In week 13 of precalc 11 we dove deeper into the whole non-permissible values thing. Somehow, Mr and Mrs. Math found a way to make it even more complicated. We now have more ways to make the denominator = 0. We can do so by adding or subtracting fractions with each other.

In last weeks reflection I forgot to mention that if the denominator is just X, you can simply write X≠0 because that works.

Now to add fractions to find the non-permissible values, lets start with a fraction like 2/x+3 + 1/x-2. Firstly we know our restrictive values can be -3 and 2, but lets do the equation so we can really find what they are. We can multiply both denominators and make the fractions have the same denominator. This will result in 2x-2/x^2-6 +x+3/x^2-6. we then add the numerators, which will result in 3x-1/X^2-6. the denominator can’t be zero and to make it 0 it will have to end up being 6-6, so x can’t be the root of 6 because x^2 will result in being 6. this means the non-permissable valv=ues are 2,-3 and √ 6. This is how you add fractions and find non-permissible values

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