Question

sin^2 t-cos^2 t ,
 если t= П/3

Answer 1

$sin^2 t-cos^2 t=-(cos^2 t-sin^2 t)=-cos2 t= \ =-cos frac{2 pi }{3} =-(- frac{1 }{2}) = frac{1 }{2}=0,5$