Answer:
Step-by-step explanation:
[tex]\frac{tan ~\alpha }{sec~\alpha -cos~\alpha } \\=\frac{\frac{sin~\alpha }{cos~\alpha } }{\frac{1}{cos~\alpha } -cos~\alpha } \\multiply~numerator~and~denominator~by~cos~\alpha \\=\frac{sin~\alpha }{1-cos^2~\alpha }=\frac{sin~\alpha }{sin ^2~\alpha } \\=\frac{1}{sin~\alpha } \\=cosec~\alpha[/tex]
