Question

$<var>sin^{2}30\textdegree+cos^{2}45\textdegree =\frac{3}{4} </var>$

Answer 1

sin 30 grade= 1/2

sin² 30 grade= (1/2)²= 1/4

cos 45 grade= √2/2

cos² 45 grade= (√2/2)²= 2/4

sin² 30 + cos² 45= 1/4 + 2/4= 3/4

Answer 2

sin 30= 1 supra 2,
sin pătrat 30= 1 supra 4.
cos 45= √2 supra 2=
cos pătrat de 45= √2² supra 2²= 2 supra 4
1 supra 4 + 2 supra 4= 3 supra 4, qed