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`int sin(2x)/(sin^4x+cos^4x) dx`A. ` tan ^( - 1 ) (cot ^ 2 x ) + C `B. ` - tan ^( - 1 ) ( cos 2x ) + C `C. ` tan ^( - 1 ) ( sin 2x ) + C `D. ` tan ^( -1 ) ( tan ^ 2 x) +C ` |
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Answer» Correct Answer - B Let I ` = int ( sin 2x ) /( sin ^ 4 x + cos ^ 4 x ) dx ` ` I = int ( sin 2x )/( ( sin ^ 2 x + cos ^ 2 x ) ^ 2 - 2 sin ^ 2 x * cos ^ 2 x ) dx ` I ` = int ( sin 2x )/ ( 1 - (1 )/ (2 ) ( sin 2x )^ 2 ) dx ` ` = 2 int ( sin 2 x ) /( 1 + ( 1 - sin ^ 2 2x ) ) dx ` (let ` t = cos 2x rArr dt = - 2 sin 2x dx ` ` = int ( -dt )/( 1 + t ^ 2 ) ` ` =- tan ^( - 1) t + C ` ` =-tan ^( - 1 ) ( cos 2x) + C ` |
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