Question

calculati sin²30-cos²60

Answer 1

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