Step-by-step explanation:
[tex] \sec( \alpha ) - \cos( \alpha ) [/tex]
[tex] \frac{1}{ \cos( \alpha ) } - \cos( \alpha ) [/tex]
[tex] \frac{1}{ \cos( \alpha ) } - \frac{ \cos {}^{2} ( \alpha ) }{ \cos( \alpha ) } [/tex]
[tex] \frac{ \sin {}^{2} ( \alpha ) }{ \cos( \alpha ) } [/tex]
[tex] \frac{ \sin( \alpha ) }{ \cos( \alpha ) } \times \frac{ \sin( \alpha ) }{1} [/tex]
[tex] \tan( \alpha ) \sin( \alpha ) [/tex]
4 is the option