let f be a continuous function over an interval I containing a critical point c such that f is differentiable over I except possibly at c; if f′ changes sign from positive ...let f be a continuous function over an interval I containing a critical point c such that f is differentiable over I except possibly at c; if f′ changes sign from positive to negative as x increases through c, then f has a local maximum at c; if f′ changes sign from negative to positive as x increases through c, then f has a local minimum at c; if f′ does not change sign as x increases through c, then f does not hav…
let f be a continuous function over an interval I containing a critical point c such that f is differentiable over I except possibly at c; if f′ changes sign from positive ...let f be a continuous function over an interval I containing a critical point c such that f is differentiable over I except possibly at c; if f′ changes sign from positive to negative as x increases through c, then f has a local maximum at c; if f′ changes sign from negative to positive as x increases through c, then f has a local minimum at c; if f′ does not change sign as x increases through c, then f does not hav…