Add or subtract as indicated; then use fundamental identities to simplify the expression below and determine which of the following is not equivalent.
$\sin x + 1 + \frac { 1 } { \sin x - 1 }$
A) $\frac { \sin ^ { 2 } x } { \sin x - 1 }$
B) $\frac { 1 - \cos ^ { 2 } x } { \sin x - 1 }$
C) $\frac { 1 + \cos ^ { 2 } x } { \sin x - 1 }$
D) $\frac { \sec x - \cos x } { \tan x - \sec x }$
E) $\frac { \csc x - \cot x \cos x } { 1 - \csc x }$

Question

Quizplus · Accepted Answer

The expression $\sin x + 1 + \frac { 1 } { \sin x - 1 }$ can be simplified to $\frac { \sin ^ { 2 } x } { \sin x - 1 }$ using the identity $\sin^2 x = 1 - \cos^2 x$. Option C, $\frac { 1 + \cos ^ { 2 } x } { \sin x - 1 }$, does not simplify to the same expression as it does not use the identity correctly.

Add or Subtract as Indicated; Then Use Fundamental Identities to Simplify