Suppose theta and phi(ne 0) are such tha...

Suppose `theta and phi(ne 0)` are such that sec `(theta+phi), sec theta and sec (theta-phi)` are in A.P. If `cos theta=kcos((phi)/(2))` for some k, then k is equal to

A

`pm 1`

B

`pm 2`

C

`pmsqrt2`

D

`pm (1)/(sqrt2)`

Verified by Experts

The correct Answer is:

C

TRIGONOMETRIC FUNCTIONS OF COMPOUND ANGLES
TARGET PUBLICATION|Exercise COMPETITIVE THINKING|101 Videos
STRAIGHT LINE
TARGET PUBLICATION|Exercise EVALUATION TEST|10 Videos
TRIGONOMETRIC FUNCTIONS
TARGET PUBLICATION|Exercise EVALUATION TEST|10 Videos

Similar Questions

Explore conceptually related problems

If cos(theta-phi),cos(theta),cos(theta+phi) are in HP, the the value of cos(theta)sec((phi)/(2)) is

If cos(theta+phi)=m cos(theta-phi) then tan theta is equal to

If sin theta=5sin(theta+phi) then tan(theta+phi)=

If 3tan theta tan phi=1. Prove that 2cos(theta+phi)=cos(theta-phi)

If theta and phi are acute angle related by a sec theta+b sec phi=c;a,b,c>0, then a cos theta+b cos phi is

If sin theta=k sin(theta+phi), show that tan(theta+phi)=(sin phi)/(cos phi-k)

If 0 lt theta , phi lt pi and 8 cos theta cos phi cos (theta + phi)+1=0 find theta and phi

If cos theta=(a cos phi+b)/(a+b cos phi) then tan^(2)((theta)/(2)) is equal to

cos 2 (theta+ phi) +4 cos (theta + phi ) sin theta sin phi + 2 sin ^(2) phi=