1, μx 1+( 1-μ)x2: consider setting score points;

2.2f [μ x1+(1-μ) x2] ≤ μ f (x1)+(1-μ) f (x2): In fact, the real meaning of this formula is "the function value at the splitting point is less than or equal to the sum of the function values at both ends". What do you think it is? This function should satisfy a concave function or a linear function (because there is an equal sign).

3. Does the condition satisfy "2f [μ x1+(1-μ) x2] ≤ μ f (x1)+(1-μ) f (x2)"?

Answer: 1 and 3 will do.