Given the inequality:
tan(x)≥2To solve this inequality, we must first solve the corresponding equation:
tan(x)=2Solve:
Given the equation
tan(x)=2- this is the simplest trigonometric equation
This equation is transformed to
x=πn+atan(2)Or
x=πn+atan(2), where n - is a integer
x1=πn+atan(2)x1=πn+atan(2)This roots
x1=πn+atan(2)is the points with change the sign of the inequality expression.
First define with the sign to the leftmost point:
x0≤x1For example, let's take the point
x0=x1−101=
(πn+atan(2))+−101=
πn−101+atan(2)substitute to the expression
tan(x)≥2tan(πn−101+atan(2))≥2tan(-1/10 + pi*n + atan(2)) >= 2
but
tan(-1/10 + pi*n + atan(2)) < 2
Then
x≤πn+atan(2)no execute
the solution of our inequality is:
x≥πn+atan(2) _____
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x1