Which of the following would be an acceptable first step in simplifying the expression sin(x)/1-cos(x)?


A. sin(x) - (sin(x)/cos(x))

B. 1/(csc(x))-(cos(x))

C. Cannot be simplified further

D. (sin(x)(1+cos(x))/(1-cos(x))(1+cos(x))

CORRECT ANSWER IS NOT C

Which of the following would be an acceptable first step in simplifying the expression sinx1cosxA sinx sinxcosxB 1cscxcosxC Cannot be simplified furtherD sinx1c class=

Respuesta :

Answer:

D)    [tex]\frac{sin x}{1-cos x} X\frac{1+cos x}{1+cosx}[/tex]

Step-by-step explanation:

Given Expression

                         [tex]\frac{sin x}{1-cos x}[/tex]

Rationalizing

                 =  [tex]\frac{sin x}{1-cos x} X\frac{1+cos x}{1+cosx}[/tex]

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

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

cancellation, sin x we get

                  [tex]= \frac{1-cos x}{sin x}\\ = \frac{2sin^{2} ({\frac{x}{2} } )}{2sin(\frac{x}{2} ) cos(\frac{x}{2}}[/tex]             ( by using trigonometry formulas

                                                         [tex]1-cos A = 2 sin^{2} (\frac{A}{2} )[/tex]

                                                          [tex]sin A = 2 sin(\frac{A}{2} ) cos(\frac{A}{2} )[/tex]  )

                  [tex]= \frac{sin({\frac{x}{2} } )}{ cos(\frac{x}{2}}[/tex]

                  [tex]= tan (\frac{x}{2} )[/tex]

Final answer:-

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