[Toán 11] Lượng giác

N

niemkieuloveahbu

Dùng đánh giá nhé.

[TEX]VP=2(1+sin^22x)\geq 2(1+0)=2[/TEX]
[TEX]VT=1.cos3x+1.\sqrt{2-cos^23x}\leq \sqrt{[1^2+1^2][cos^23x+(2-cos^23x)]}=2\\\Rightarrow \{sin2x=0\\cos3x=1[/TEX]

[TEX]\Leftrightarrow x=k2\pi, k\in Z[/TEX]

OK nhé
 
You must log in or register to reply here.
Top Bottom