\(\left(3tanx+\sqrt{3}\right)\left(2sinx-1\right)=0\Leftrightarrow\left[\begin{array}{nghiempt}tanx=\frac{-\sqrt{3}}{3}\\sinx=\frac{1}{2}\end{array}\right.\)
\(TH1:tanx=\frac{-\sqrt{3}}{3}\Leftrightarrow x=\frac{-\pi}{6}+k\pi\\ TH2:sinx=\frac{1}{2}\Leftrightarrow\left[\begin{array}{nghiempt}x=\frac{\pi}{6}+k2\pi\\x=\frac{5\pi}{6}+k2\pi\end{array}\right.\)
Giải PT
a) sin2 x + 2sinx - 3 = 0
b) 2cos x + cos 2x = 0
c) tanx + cotx + 2 = 0
d) sinx + cos2x + 1 = 0
e) tan x + cot 2x = 0
Giair các pt lượng giác sau:
1) \(sin\left(x-\frac{\pi}{4}\right)\left(2cos+\sqrt{2}\right)tan2x=0\)
2) \(tan2x.sinx+3\left(sin-\sqrt{3}tan2x\right)-3\sqrt{3}=0\)
3) \(\frac{cos2x}{sin\left(x+\frac{3\pi}{4}\right)}=\frac{sin\left(x+\frac{3\pi}{4}\right)}{cos2x}\)
4) \(\left(\frac{tanx-1}{tanx+1}+cot2x\right)\left(3tan-\sqrt{3}\right)=0;0< x< \pi\)
Giải phương trình lượng giác
\(\sqrt{3-4cos2x}-\sqrt{2sinx}=0\)
3sinx - \(\sqrt{4sin^2x-1}=1\)
giải pt
a) \(tan\left(x+\frac{\pi}{3}\right)=cot\left(3x-\frac{\pi}{6}\right)\)
b) \(\left(\sqrt{3}-\frac{3}{tanx}\right).tanx=0\)
(2sinx+1)2 + (2sinx +1) (sinx -\(\frac{3}{2}\))= 0
giải pt
a) \(cosx\left(3tanx-\sqrt{3}\right)=0\)
b) \(\frac{\left(2-sinx\right)\left(\sqrt{3}cosx-1\right)}{1+sinx}+2=sinx\)
c) \(\frac{tanx-sinx}{sin^3x}=\frac{1}{cosx}\)
d) \(\frac{sin3x.cosx-sinx.cos3x}{cos^2x}=2\sqrt{3}\)
\(tan\left(\frac{\Pi}{3}-3x\right)+tan2x+tanx=\sqrt{3}\)
\(tan\left(\frac{\Pi}{3}-3x\right)+tan2x+tanx=\sqrt{3}\)
\(tan\left(\frac{\Pi}{3}-3x\right)+tan2x+tanx=\sqrt{3}\)
\(4sin^2\left(x+\frac{\Pi}{6}\right)+sin2x=1\)
