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calculati sin²30-cos²60

Răspuns :

sin 30= 1/2
cos 60= 1/2
[tex] sin^{2} 30- cos^{2} 60 = ( \frac{1}{2}) ^{2} - ( \frac{1}{2}) ^{2} = \frac{1}{4} - \frac{1}{4} =o[/tex]