integrating trig functions (1 Viewer)

kr73114

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inegrate: 0-pi/4 [sin2xcos2x.dx]
i know you could use reverse chain rule but this question says use the compund angle formula
 
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inegrate: 0-pi/4 [sin2xcos2x.dx]
i know you could use reverse chain rule but this question says use the compund angle formula
use double angle formula for sin2x

sin2x= 2sinxcosx therefore sinxcosx = (1/2) sin(2x)

therefore sin(2x)cos(2x) = (1/2) sin(4x) now its easy to integrate

= -(1/8) [cos(4x)] between the limits etc etc
 

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