Giai Pt
\(\left(2sinx-cosx\right)\left(1+cosx\right)=sin^2x\)
\(3sin^2x+7cos2x-3=0\)
\(\dfrac{4sin^2x+6sin^2x-9-3cos2x}{cosx}=0\)
Giải pt
\(2sin\left(x+\dfrac{\pi}{6}\right)+sinx+2cosx=3\)
\(\left(sin2x+cos2x\right)cosx+2cos2x-sinx=0\)
\(sin2x-cos2x+3sinx-cosx-1=0\)
Giải pt
\(sinx-\sqrt{2}cos3x=\sqrt{3}cosx+\sqrt{2}sin3x\)
\(sinx-\sqrt{3}cosx=2sin5x\)
\(\sqrt{3}cos5x-2sin3xcos2x-sinx=0\)
\(sinx+cosxsin2x+\sqrt{3}cos3x=2\left(cos4x-sin^3x\right)\)
\(tanx-3cotx=4\left(sinx+\sqrt{3}cosx\right)\)
Giai pt
\(5sinx-2=3\left(1-sinx\right)tan^2x\)
\(2.cos2x.cosx=1+cos2x+cos3x\)
\(cos2x+cosx=4sin^2\left(\dfrac{x}{2}\right)-1\)
Giai pt
\(5sinx-2=3\left(1-sinx\right)tan^2x\)
\(2.cos2x.cosx=1+cos2x+cos3x\)
\(cos2x+cosx+4sin^2\left(\dfrac{x}{2}\right)-1\)
Giải các pt sau :
a, \(sin\dfrac{x}{2}\cdot sinx-cos\dfrac{x}{2}\cdot sin^2x+1-2cos^2\cdot\left(\dfrac{\pi}{4}-\dfrac{x}{2}\right)=0\)
b, \(tanx-3cotx=4\cdot\left(sinx+\sqrt{3}\cdot cosx\right)\)
\(1.\left(sinx+cosx\right)^3+sinxcosx-1=0\)
\(2.\left(sinx+cosx\right)^4-3sin2x-1=0\)
\(3.sin^3x+cos^3x+2\left(sinx+cosx\right)-3sin2x=0\)
\(4.\left(sinx-cosx\right)^3=1+sinxcosx\)
5.\(sinx+cosx+2+tanx+cotx+\frac{1}{sinx}+\frac{1}{cosx}=0\)
Tìm nghiệm \(x\in\left(0;10\pi\right)\) của phương trình
\(\dfrac{\sqrt{3}}{cos^2x}-tanx-2\sqrt{3}=sinx\left(1+tanx.tan\dfrac{x}{2}\right).\)
Giải: \(2\sqrt{2}cos^3\left(x-\dfrac{\pi}{4}\right)-3cosx-sinx=0\)