Tangent scaling can be used directly. The essence of tangent scale method is to solve a class of multivariate problems by using the image properties of functions and transform them into inequalities for finding the maximum value and type of univariate functions. At this time, you can choose to look for the second derivative to see the concavity and convexity, and judge whether the tangent method can be used or better. You can also directly choose to find the first derivative, find the tangent value of the equal path condition, and match the constant term of the corresponding inequality with the last constant coefficient.

Application of Tangent Scaling

Tangent proportion method is a classic test method in the exam, and the most classic inequalities are: e x >；; =x+ 1, linx < = x-1and its deformation. Tangent scaling can be converted into straightness, transcendental function can be converted into linear or non-transcendental function, which is convenient to handle and can realize local approximate simulation. It is the key to pay attention to the shape of the function and grasp its concavity and convexity and its changing trend. Usually, the tangent bridge method is used to prove the problem.