A. 16R2-( a2+b2+c2)
B. 16R2-( a2+b2-c2)
C. 16R2-( a2-b2+c2)
D. 16R2-( a2-b2-c2)
A man observes that angle of elevation of the top of a tower from a point P on the ground is θ. He moves a certain distance towards the foot of the tower and finds that the angle of elevation of the top has doubled. He further moves a distance 3/4 of the previous and finds that the angle of elevation is three times that at P. Then angle θ is given by
If a. cos (θ+ α)= b cos (θ-α), then (a+b) tan θ=
If α,β are solutions of a cos 2θ+b sin 2θ=c, then tan α tan β=
If sin A= sin2 B and 2 cos2 A =3 cos2 B, then the ΔABC is
In ΔABC, if A=900 then r2 +r3 =