If cos (theta - alpha) , cos theta , cos...

If `cos (theta - alpha) , cos theta , cos (theta + alpha ) ` are in H.P. then ` cos theta .sec"" (alpha )/(2) =`

A

1

B

`+-2`

C

`sqrt3`

D

`+-sqrt2`

Text Solution

Verified by Experts

The correct Answer is:

D

Topper's Solved these Questions

MULTIPLE & SUBMULTIPLE ANGLES
AAKASH SERIES|Exercise PRACTICE EXERCISE|68 Videos
MULTIPLE & SUBMULTIPLE ANGLES
AAKASH SERIES|Exercise EXERCISE-1 |35 Videos
MULTIPLE & SUBMULTIPLE
AAKASH SERIES|Exercise PRACTICE SHEET (EXERCISE - II) (LEVEL - II) (Linked Comprehension Type Questions)|5 Videos
MULTIPLE PRODUCT OF VECTORS
AAKASH SERIES|Exercise PRACTICE EXERCISE|62 Videos

Similar Questions

Explore conceptually related problems

If sec ( theta - alpha ) , sec theta , sec ( theta + alpha ) are in A.P. then cos theta =

If sec ( theta + alpha ) , sec theta , sec (theta - alpha ) are in A.P. Then cos theta sec alpha //2=

If cos 2theta + cos 8theta = cos 5theta then theta =

If cos theta + cos 2theta + cos 3theta = 0 then theta =

1+ cos 2 theta + cos 4 theta + cos 6 theta =

If sin ( theta + alpha ) = cos ( theta + alpha ) , then tan theta =

cos ( theta + alpha)* cos ( theta - alpha) + sin ( theta + alpha) * sin (theta - alpha )=

If cos theta=-cos theta, then theta is

AAKASH SERIES-MULTIPLE & SUBMULTIPLE ANGLES-EXERCISE-II

2 sin^(2) beta + 4 cos( alpha+ beta) sin alpha sin beta + cos ( 2 alph...
Text Solution
|
If A and B are acute angles satisfying 3sin^(2)A+2sin^(2)B=1 and 3 sin...
Text Solution
|
If cos (theta - alpha) , cos theta , cos (theta + alpha ) are in H.P....
Text Solution
|
A quadratic equation whose roots are sin^(2) 18^(@) , cos^(2) 36^(@) ...
Text Solution
|
Prove that (1)/(cos 290^(@))+(1)/(sqrt3 sin 250^(@) )=(4)/(sqrt3)
Text Solution
|
Prove that sqrt3 csc 20 ^(@)- sec 20^(@)=4
Text Solution
|
sin6^(@)sin42^(@)sin66^(@)sin78^(@)=
Text Solution
|
If A=tan6^(@) tan42^(@), B=cot66^(@) cot78^(@) then
Text Solution
|
cos6^(@)sin24^(@)cos72^(@)=
Text Solution
|
Prove that cos. (pi)/(11). cos . (2 pi)/(11). cos . (3 pi)/(11) cos. (...
Text Solution
|
"Cos"(2pi)/15."Cos"(4pi)/15."Cos"(8pi)/15."Cos"(14pi)/15=
Text Solution
|
If 630^@ lt A lt 720^(@) , |tan A|=12//5, " then " tan A//2=
Text Solution
|
Prove that (1+cos""pi/10)(1+cos""(3pi)/10)(1+cos""(7pi)/10)(1+cos""(9p...
Text Solution
|
"cos"^(2)pi/10+"cos"^(2)(2pi)/5+"cos"^(2)(3pi)/5+"cos"^(2)(9pi)/10=
Text Solution
|
Show that cos^4""pi/8+cos^4""(3pi)/8+cos^4""(5pi)/8+cos^4""(7pi)/8=3/2
Text Solution
|
tan9^(@)-tan27^(@)-tan63^(@)+tan81^(@)=
Text Solution
|
x/(costheta)=y/(cos(theta-(2pi)/3))=z/(cos(theta+(2pi)/3)) then x+y+z=
Text Solution
|
The minimum value of cos^(3) x+ cos^(3) (120^(@) + x) + cos^(3) (120^...
Text Solution
|
If x= tan15^(@) , y="cosec"75^@ and z= 4 sin18^(@) , then
Text Solution
|
cos^(2)(alpha+beta)+cos^(2)(alpha-beta)-cos2alpha cos2beta=
Text Solution
|