Flag Integral Calculus> Evaluate the following pls helpIntegratio...
question mark

Evaluate the following pls helpIntegration sin3xcos5x dx

Shubham Kumar , 8 Years ago
Grade 11
anser 1 Answers
Vikas TU
We know that sin(A+B) = sinAcosB + cosAsinB -----------------1
We know that sin(A - B) = sinAcosB - cosAsinB -----------------2

Now adding 1 and 2

2sinAcosB = 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
Last Activity: 8 Years ago
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments