Sin²x tan²x = tan²x - sin²x

[tex]\displaystyle \sin^2x\tan^2x=\tan^2x-\sin^2x\\\sin^2x\cdot\frac{\sin^2x}{\cos^2x}=\tan^2x-\sin^2x\\\frac{\sin^2x\cdot\sin^2x}{\cos^2x}=\tan^2x-\sin^2x\\\frac{\sin^2x\cdot(1-\cos^2x)}{\cos^2x}=\tan^2x-\sin^2x\\\frac{\sin^2x-\cos^2x\sin^2x}{\cos^2x}=\tan^2x-\sin^2x\\\frac{\sin^2x}{\cos^2x}-\sin^2x=\tan^2x-\sin^2x\\\boxed{\boxed{\tan^2x-\sin^2x=\tan^2x-\sin^2x}}[/tex]

Identitas Trigonometri.
Kelompok wajib kelas X kurikulum 2013 revisi 2016.

sin² x tan² x
= (1 - cos² x) tan² x
= tan² x - cos² x tan² x
= tan² x - cos² x (sin x / cos x)²
= tan² x - sin² x
Terbukti.