Some (General?) Methods

Making up Proportion

in Inequality

2

\((x\bar a+y\bar b+z\bar c)^2=...\)

Making up function and number sequence

Construct a constant function or a constant number sequence that satisfies the multiple-choice question whenever possible.

Skip the step of construct \(g(x)\)

......+\(f'(x)\)+.........\(<0 \iff\) \(g'(x) < 0\)

Specific value: 2D -> 1D

Represent the two-dimensional figure described in the multiple-choice question on a one-dimensional line whenever possible.