A
The number of values of X in the interval [0,3pi] satisfying the equation 2sin 2x+ 5 sinx-3=0 is A) 4 B)6 C)1 D)2
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A
Al
Thank you
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B
Bagyashree
It is basically a quadratic equation in sinx consider sinx=t so the equation reduces to 2t^2+5t-3=0 Which implies 2t^2+6t-t-3=0 On further equating (factorising) 2t(t+3)-(t+3)=0 So (t+3)(2t-1)=0 now either t+3=0 =>t=-3(impossible as t=sinx and -1<=sinx<=1) Or 2t-1=0 =>t=½ =>sinx=½ =>x=π/6,5π/6,13π/6,17π/6 (0,3π)
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