Q9 of 80 Page 311

If 2 cos 3 θ = 1, then the value of θ is

Given,


⇒ we know


∴ θ = 20


⇒ cos3(20) = cos60


⇒ Option A is incorrect as it does not satisfy the value


⇒ Option B is incorrect as it does not satisfy the value


⇒ Option D is incorrect as it does not satisfy the value

More from this chapter

All 80 →
9

If tan α + cot α = 2, then the value of (tan13 α + cot13 α) is

9

If and sec θ + cosec θ + x, then the value of x is

 9

Let us write whether the following statements are true or false :

i. If then the least value of (sec2 α + cos2 α) is 2.


ii. The value of is 1.

 9

Let us fill in the blanks :

i. The value of is ________.


ii. If then the value of cos θ is __________


iii. If then the value of cos4θ – sin4θ is __________