a) Find and classify the critical point(s).b) Find the interval(s) where f(x) is increasing.c) Find the interval(s) where f(x) is decreasing.1. f(x)=x-x-12. f(x)=2x^4 - 4x

a) Find and classify the critical point(s).b) Find the interval(s) where f(x) is increasing.c) Find the interval(s) where f(x) is decreasing.1. f(x)=x²-x-12. f(x)=2x^4 - 4x² +13. f(x)=xe^1/x