Question

(sec A-cosA)(cotA+tanA)=tanAsecA

Answer 1

(Sec a - cos a)(cot a+tan a)=tan a seca LHS=((1-cos a ^2) /cos a) (( cos ^2 a+ sin^2 a) /(cos a sin a))  =(sin^2 a) (1)/(cos ^2 a sin a)  =sin a/ cos ^2 a = tan a*sec a