Besoin daide svp !!!! Je ne comprens rien sec5

Bonjour,

[tex](sec^2\theta+cosec^2\theta)\times\sin^2\theta\\\\=(\dfrac{1}{\cos^2\theta}+\dfrac{1}{\sin^2\theta})\times\sin^2\theta}\\\\=(\dfrac{\sin^2\theta}{\sin^2\theta\cos^2\theta}+\dfrac{\cos^2\theta}{\sin^2\theta\cos^2\theta})\times\sin^2\theta}\\\\=(\dfrac{\sin^2\theta+\cos^2\theta}{\sin^2\theta\cos^2\theta})\times\sin^2\theta}\\\\=(\dfrac{1}{\sin^2\theta\cos^2\theta})\times\sin^2\theta}\\\\=\dfrac{\sin^2\theta}{\sin^2\theta\cos^2\theta}[/tex]

[tex]\\\\=\boxed{\dfrac{1}{\cos^2\theta}}\\\\=\boxed{sec^2\theta}[/tex]