Let A≡(1+sinα,cosα); B≡(1−cosβ,−sinβ). If α,β are the roots of quadratic equation 3sinθ−2sin2θ−1=0 where 0≤θ≤π2 and the distance AB=√a+√bunits, then a+b=
Open in App
Solution
Given : 3sinθ−2sin2θ−1=0 ⇒(sinθ−1)(1−2sinθ)=0 ⇒sinθ=1 or sinθ=12 ∴θ=π2orπ6 Let α=π6,β=π2 or α=π2,β=π6 in both the cases distance is same as AB=√(sinα+cosβ)2+(cosα+sinβ)2 =√2+2sin(α+β)=√2+√3 comparing with √a+√b⇒a=2,b=3 ∴a+b=5