×-9×=0
×=0*9
×=0
9×=9*0
9×=0
0-9*0=0
0=0
<span>5√3-√300-√27=</span>5√3-√3*100-√9*3=<span>5√3-10√3-3√3</span>= - 8√3
П/3=60градусов п/2=90; 5п/36=25; 2п/5=72; 3п/4=135. -п/9 =-20. п/6=30. 3п/5 =108. п=180. 5п/4=225..3п/2=270. 7п/12=105
1) cos²a+cos²a*ctg²a= cos²a(1+ctg²a)=cos²a(1+cos²a/sin²a)=cos²a(sin²a+cos²a)/sin²a=cos²a/sin²a=ctg²a
2) sin²a+sin²a*tg²a=sin²a(1+sin²a/cos²a)=sin²a(cos²a+sin²a)/cos²a=sin²a/cos²a=tg²a