Q.17. in a equilateral triangie abc, proof the follow relations. () 2cos-sin= (ii) sec a=1 +sec a (iii) -2 cos a = tan 2/2 iv) i+2 cos a- cot a/2 () log sin+log

Q.17. In a Equilateral triangie ABC, proof the follow relations. () 2cos-Sin= (ii) sec A=1 +sec a (iii) -2 cos A = tan 2/2 iv) I+2 cos a- cot A/2 () log sin+log cos,+log 2 0 2