Question

pls answer this this question​

Answer 1

Answer:

According to the given condition, if a,b,c are in G.P., we have 

ac=b2

Similarly, 

tanθsinθ×61=cos2θ

⇒sin2θ=6cos3θ

⇒6cos3θ+cos2θ−1=0

We get cosθ=21 by observation, since its value has to lie between 0 and 1.

Since cosθ=21, the general solution becomes   2nπ±3π