Grade 11Integral CalculusEvaluate the following pls helpIntegration sin3xcos5x dx Shubham Kumar 9 Years agoGrade 11
Vikas TU9 Years agoWe know that sin(A+B) = sinAcosB + cosAsinB -----------------1We know that sin(A - B) = sinAcosB - cosAsinB -----------------2Now adding 1 and 22sinAcosB = sin(A+B) + sin(A - B), so that sinAcosB = (1/2)[sin(A+B) + sin(A-B)] let A = 3x and B = 5x Rewriting the question (1/2) ∫ [sin8x + sin(-2x)] dx = (1/2) ∫ [sin8x - sin2x] dx = => -1/16 cos8x + 1/4 cos2x + C