Find all point of discontinuity of the function `f(t)=1/(t^2+t-2),` where `t=1/(x-1)`

Explanation

`f(t)=frac{1}{t^{2}+t-2}`



Now, let `u=frac{1}{x-1}`



`therefore f(u)=frac{1}{u^{2}+2 u-u-2}=frac{1}{u^{2}+u-2}=frac{1}{(u+2)(u-1)}`



So, `f(u)` is not defined at `u=-2` and `u=1`


If `u=-2`, then


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