関連ワード:  is f x a continuous function    is f(x)=x^2 a continuous function    is the function defined by f x a continuous function    let f x is a continuous function which takes positive    if f(x) is a continuous function and attains only rational values    prove that f x 4 is a continuous function    show that f x cos2x is a continuous function    f x is a continuous and differentiable function    7 is the function defined by f x a continuous function    show that f x )= cos x is a continuous function