A) \[a,b,c\] are in A.P.
B) \[\cos \,A,\,\cos B,\,\cos \,C\] are in A.P.
C) \[\sin A,\sin B,\sin C\] are in A.P.
D) [a] and [c] both
Correct Answer: D
Solution :
Here \[\frac{A}{2}\,\tan \frac{C}{2}=\frac{s-b}{s}\] \[\frac{5}{6}.\frac{2}{5}=\frac{s-b}{s}\Rightarrow 3s-3b=s\Rightarrow 2s=3b\] \[\Rightarrow \,\,\,a+b+c=3b\] or \[a+c=2b.\] \[\therefore \] a, b, care in A.P., also sin A, sin B, sin Care in A.P.
You need to login to perform this action.
You will be redirected in
3 sec
