A. 2√3
B. √21
C. 8
D. 14
If α, β are solutions of a tan θ+b sec θ=c then tan (α+β) =
If I1,I2,I3 are excentres of the triangle with vertices (0,0), (5,12), (16,12) then the orthocentre of ?I1,I2,I3 is
An observer finds that the angular elevation of a tower is θ. On advancing ‘a’ metres towards the tower, the elevation is 450 and on advancing b metres the elevation is 900-θ. The height of the tower is
A vertical tower stands on a declivity which is included at 150 to the horizon. From the foot of the tower a man ascends the declivity for 80 feet and then finds that the tower subtends an angle of 300. The height of the tower is
In ΔABC , if c2= a2+b2, 2s= a+b+c, then 4s (s-a) (s-b) (s-c) =
In a triangle ABC, if cot A = (x3+x2+x)1/2, cot B= (x+x-1+1)1/2 and cot C= (x-3+x-2+x-1) -1/2 then the triangle is
If A=(1,1) ,B=(4,5) and C=(6,13) then cos A=
In ΔABC , if A=750, B=450, C=√3, then b=
In ΔABC, if a(b cos C + c cos B) =2ka2, then k =
In ΔABC, R2 (sin 2A+sin 2B+sin 2C)=