You can put this solution on YOUR website! I worked it out with substitutions and found that sin(x) sin(2x) is never less than sin(3x) sin(4x), but they are equal when x = 0.
You can put this solution on YOUR website! Solve ;
sin(x) sin(2x) < sin(3x) sin(4x)
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I disagree with the other tutor.
The inequality is true for x = 18 degs (for 1 example)
More on it later.