Question

If cos (θ – α), cos θ and cos (θ + α) are in harmonic progression, then cosθ sec (α/2) is equal to

Solution

Correct option is

Since cos (θ – α), cos θ and cos (θ + α) are in H.P., we have

         

   

      

     

   

SIMILAR QUESTIONS

Q2
Q3

Which of the following statement is correct

Q4

 then the value of tan α tan 2α tan 3α….tan(2n-1)α is equal to

Q5

The number of solution of the equation

  is/are

   

Q6
Q7

If tan x = 2b/(a – c) (a  c), y = a cos2 x + 2b sin x cos x + c sin2 c and z = a sin2 x – 2b sin x cos x + c cos2 x, then

Q8
Q9

If A and B are acute angles such that sin A = sin2 B, 2cos2 A = 3 cos2 B; then

Q10

If A and B are acute angles such that A + B and A – B satisfy the equation tan2 θ – 4 tan θ + 1 = 0, then find the value of A and B.