Write the solution set of the equation(2 cos θ+1)(4 cos θ+5)=0 in the interval[0,2π].
We have,(2 cos θ+1)(4 cos θ+5)=0⇒csoθ=−12 or cos θ =−54Since cosθ ≠ −54 for any value of x the only solutins of the given equation in [0,2π]are x =2π3,4π3.
The solution set of the equation 4sinθ−2cosθ−2√3sinθ+√3=0 in the interval (0,2π) is-