∫ sin mx cos nx dx, m ≠ n
We know 2sinAcosB = sin(A + B) + sin(A – B)
∴ sinmxcosnx = 
∴ The above equation becomes
⇒ 
We know 
⇒ 
⇒ 
4
∫ sin mx cos nx dx, m ≠ n
We know 2sinAcosB = sin(A + B) + sin(A – B)
∴ sinmxcosnx =
∴ The above equation becomes
⇒
We know
⇒
⇒