Example 1[ 1] Let the function f(x) be differentiable in the interval [0, 1], and f' (x) ≠ 1, 0f (x) 1 (0 ≤ x ≤ 650). We assume that the equation (1) has another real root θ η between 0 and 1. Because f (θ) = f (η let f' (ξ) = f' (ξ)-1= 0. F'(ξ)= 1, which is contrary to the condition of the topic. Therefore, the equation (1) has only one real value between 0 and 1.