Respuesta :
Answer: 1
Step-by-step explanation:
Alright, lets get started.
The given expression is :
[tex]\frac{sin^2x-1}{cosx}=-1[/tex]
As per Pythagorean identity,
[tex]sin^2x + cos^2 x = 1[/tex]
taking 1 to left side and [tex]cos^2 x[/tex] to right side
[tex]sin^2 x-1=-cos^2x[/tex]
Now plugging the value of [tex]sin^2 x-1[/tex] in given expression
[tex]\frac{-cos^2x}{cosx} =-1[/tex]
cosx will be cancelled, so
[tex]-cosx=-1[/tex]
Multiplying -1 in both sides, it will equal to
[tex]cos x= 1[/tex] ........................ Answer (C)
Hope it will help :)
