Set 2sin2x+3sinx−2>0 and x2−x−2<0 (x is measured in radians). Then x lies in the interval
A
(π/6,5π/6)
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B
(−1,5π/6)
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C
(−1.2)
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D
(π/6,2)
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Solution
The correct option is D(π/6,2) x2−x−2<0 ⇒(x+1)(x−2)<0 i.e xϵ(−1,2)⟶(1) Also given, 2sin2x+3sinx−2>0 ⇒(2sinx−1)(sinx+2)>0 we know −1≤sinx≤1⇒sinx+2>0 ⇒2sinx−1>0 ⇒12<sinx≤1⟶(2) considering (1) and (2), solution is, xϵ(π6,2) Hence, option 'D' is correct.