Given the inequality: tan(x)>3(−1)3 To solve this inequality, we must first solve the corresponding equation: tan(x)=3(−1)3 Solve: Given the equation tan(x)=3(−1)3 - this is the simplest trigonometric equation This equation is transformed to x=πn+atan(−33) Or x=πn−6π , where n - is a integer x1=πn−6π x1=πn−6π This roots x1=πn−6π is the points with change the sign of the inequality expression. First define with the sign to the leftmost point: x0<x1 For example, let's take the point x0=x1−101 = (πn−6π)−101 = πn−6π−101 substitute to the expression tan(x)>3(−1)3 tan(πn−6π−101)>3(−1)3