Solution
$$\tan^4 x - \tan^2 x = 1$$
$$=$$> $$\tan^4x=1+\tan^2x$$
$$=$$> $$\tan^4x=\sec^2x$$
$$=$$> $$\tan^2x=\sec x$$
$$=$$> $$\frac{\sin^2x}{\cos^2x}=\frac{1}{\cos x}$$
$$=$$> $$\sin^2x=\cos x$$
$$\therefore\ \sin^4x+\sin^2x=\left(\sin^2x\right)^2+\sin^2x$$
$$=\left(\cos x\right)^2+\sin^2x$$
$$=\cos^2x+\sin^2x$$
$$=1$$
Hence, the correct answer is Option AGet AI Help
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