Which of the following is the greates? `cos e c1` (b) `cos e c2` `cos e c4` (d) `cos e c(-6)`

Suppose ABCD (in order) is a quadrilateral inscribed in a circle. Which of the following is/are always true? (a) secB=secD (b) cotA+cotC=0 (c) cos e cA=cos e cC (d) tanB+tanD=0

Which of the following quantities are rational? (a) sin((11pi)/(12))sin((5pi)/(12)) (b) cos e c((9pi)/(10))sec((4pi)/5) (c) sin^4(pi/8)+cos^4(pi/8) (d) (1+cos(2pi)/9)(1+cos(4pi)/9)(1+cos(8pi)/9)

In A B C , prove that cos e c A/2+cos e c B/2+cos e c C/2geq6.

The value of cos e c10^0+cos e c50^0-cos e c70^0 is ____

State which of the following sets are disjoint. R = {a, b, c, d, e}, S = {d, e, b, c, a}

Find the sum of the series cos e ctheta+cos e c2theta+cos e c4theta+ tont e r m sdot

If I is the incenter of a triangle ABC, then the ratio I A : I B : I C is equal to a) cos e c A/2: cos e c B/2: cos e c C/2 b) sinA/2:sinB/2:sinC/2 c) secA/2:secB/2:secC/2 d) none of these

If A+B+C=pi/2 prove the following (i) sin 2A+sin 2B +sin 2C=4 cos A cos B cos C (ii) cos 2A +cos 2B+cos 2C=1+4 sin A sin B sin C.

Prove that cos (A + B) cos C - cos (B + C) cos A = sin B sin (C - A)