Giải phương trình sau:

Sin ( π sin x ) =1

Giải phương trình:
\(\frac{cos^2x}{1-sinx}=\frac{sin^2x}{1-cosx}\)

Chứng minh rằng:

\(\frac{\sin^22x-4\sin^2x}{\sin^22x+4\sin^2x-4}=tan^4x\)

(Mấy bồ ơi, giúp với nè!)

\(\sqrt{2x+\sqrt{6x+1}}>x+1\)

Chứng minh rằng: (Pls help me)
a, \(\frac{1}{\sin x}+\cot x=\cot\frac{x}{2}\)

b, \(\frac{1-\cos x}{\sin x}=\tan\frac{x}{2}\)

c,\(\tan\frac{x}{2}\left(\frac{1}{\cos x}+1\right)=\tan x\)

d,\(\frac{\sin2a}{2\cos a\left(1+\cos a\right)}=\tan\frac{a}{2}\)

e,\(\cot x+\tan\frac{x}{2}=\frac{1}{\sin x}\)

f,\(3-4\cos2x+\cos4x=8\sin^4x\)

g,\(\frac{1-\cos x}{\sin x}=\frac{\sin x}{1+\cos x}\)

h,\(\sin x+\cos x=\sqrt{2}\sin\left(x+\frac{\pi}{4}\right)\)

i,\(\sin x-\cos x=\sqrt{2}\sin\left(x-\frac{\pi}{4}\right)\)

l,\(\cos x-\sin x=\sqrt{2}\cos\left(x+\frac{\pi}{4}\right)\)