3)1/cos²a-1=tg²a+1-1=tg²a
tg²(π/3)=3
4)cos²a+tg²a×ctg a+sin²a= cos²a+sin(a)/cos(a)+sin²a= tg a+1
tg(π/3)+1=√3+1
3)1/cos²a-1=tg²a+1-1=tg²a
tg²(π/3)=3
4)cos²a+tg²a×ctg a+sin²a= cos²a+sin(a)/cos(a)+sin²a= tg a+1
tg(π/3)+1=√3+1