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Grade 12Integral Calculus

inegration of (sinx + cosx)/3+sin2x dx......................................

Profile image of Sara
7 Years agoGrade 12
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2 Answers

Profile image of Tech Xposed
ApprovedApproved Tutor Answer7 Years ago
The answer is:-
  1. bring the denominator in (sin x – cosx)^2 format
  2. then take sin x- cos x= t
  3. therfore sin x + cos x dx = dt
  4. then the question will be converted into dt/a^2 – t^2 format then we can apply the formula.
\int \frac{sinx+cosx}{3+sin2x} =\int \frac{sinx+cosx}{4-1+sin2x} =\int \frac{sinx+cosx}{4-(1-sin2x)} =\int \frac{sinx+cosx}{4-(sin^{2}x+cos^{2}x-sin2x)} =\int \frac{sinx+cosx}{4-(sinx-cosx)^{2}} let sin x- cos x =t => (cos x +sin x )dx = dt =\int \frac{dt}{4-t^2} = \frac{1}{2*2} ln\frac{2+t}{2-t} = \frac{1}{2*2} ln\frac{2+sinx-cosx}{2-sinx+cosx}
Profile image of Rishi Sharma
5 Years ago
Dear Student,
Please find below the solution to your problem.

bring the denominator in (sin x – cosx)^2 format
then take sin x- cos x= t
therfore sin x + cos x dx = dt
then the question will be converted into dt/a^2 – t^2 format then we can apply the formula

Thanks and Regards