The vertices of a triangle are A(1,-1,2) ,B(6,11,2),C(1,2,6) then cos A=
(A) `(63)/(65)` (B) `(36)/(65)` (C) `(16)/(65)` (D) `(13)/(65)`

The vertices of a triangle are A(1,1),B(4,5) and C(6,13). Find cos A

The vertices of a triangle are A(1,1),B(4,5) and C(6,13) Find cos A.

The cosine of the angle of the triangle with vertices A(1,-1,2),B(6,11,2) and C(1,2,6) is

cos ^ (- 1) ((4) / (5)) + cos ^ (- 1) ((63) / (65)) =

cos^(-1)((63)/(65))+2tan^(-1)((1)/(5))=sin^(-1)(3/5)

Prove that cos^(-1)((3)/(5))+cos^(-1)((12)/(13))+cos^(-1)((63)/(65))=(pi)/(2)

The value of sin^(-1)((12)/(13)) - sin ^(-1)((3)/(5)) is equal to (A) pi-sin ^(-1) ((63)/(65)) (B) (pi)/(2) - sin ^(-1)((56)/(65)) (C) (pi)/(2) - cos ^(-1)((9)/(65)) (D) pi - cos ^(-1)((3)/(65))

Prove that sin ^ (- 1) ((63) / (65)) = sin ^ (- 1) ((5) / (13)) + cos ^ (- 1) ((3) / (5))

cos^(-1) (63/65) + 2tan^(-1) (1/5)= sin^(1) (_______).

Prove that cot^(-1).(3)/(4) + sin^(-1).(5)/(13) = sin^(-1).(63)/(65)