If in a `/_\ ABC, a=6, b=3 and cos(A-B)= 4/5` then (A) `C=pi/4` (B) `A=sin^-1 2/sqrt(5)` (C) `ar(/_\ ABC)=9` (D) none of these

sin^-1 (-1/2)+tan^-1 (sqrt(3))= (A) -pi/6 (B) pi/3 (C) pi/6 (D) none of these

sin^-1 (cos(sin^-1(sqrt(3)/2))= (A) pi/3 (B) pi/6 (C) - pi/6 (D) none of these

In /_\ABC , if sin A= 1/3 and sin B= 1/4 , sin C=

In an isosceles right angled triangle ABC, /_B=90^0, AD is the median then (sin/_BAD)/(sin/_CAD) is (A) 1/sqrt(2) (B) sqrt(2) (C) 1 (D) none of these

If sin^(-1)x-cos^(-1)x=pi/6 , then x= (a) 1/2 (b) (sqrt(3))/2 (c) -1/2 (d) none of these

In any triangle ABC, the least valeu of (sin^2A+sinA+1)/(sinA)is (A) 3 (B) sqrt(3) (C) 9 (D) none of these

In a given /_\ ABC ,D E||B C and (A D)/(D B)=3/5dot If A C=5. 6 , find A E .

In triangle ABC , if a=3, b=4, and c=5, then find the value of cosA.

If f,g,h are the internal bisectors of a /_\ ABC then 1/f cos (A/2)+ 1/g cos (B/2) +1/h cos (C/2)= (A) 1/a+1/b-1/c (B) 1/a-1/b+1/c (C) 1/a+1/b+1/c (D) none of these

In a triangle ABC, a^4+b^4+c^4=2a^2b^2+b^2c^2+2a^2c^2 then sinA is equal to (A) 1/sqrt(2) (B) 1/2 (C) sqrt(3)/2 (D) none of these