Question

Find the principal solution of the equation
cosx=
- √ 3/2


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Answer 1

Question :-

• Find the principal solution of the equation : cosx = - √3/2

Answer

Given :-

• cosx = - √3/2

To find :-

• Principal Solution

Concept used :-

• If the equation involves a variable 0 ≤ x < 2π, then the solutions are called principal solutions. 
• Or
• The solutions such trigonometry equations which lie in the interval of [0, 2π] are called principal solutions. 

Solution :-

cosx = - √3/2

⇛ cosx is negative.

⇛ x lies in second or third quadrant.

⇛ x =  π - π/6 or π + π/6

⇛ x =  5π/6 or 7π/6.