- #1
cragar
- 2,552
- 3
If I have [itex] \int e^{2x}sin(x)sin(2x) [/itex]
And then I use Eulers formula to substitute in for the sine terms.
So I have [itex] \int e^{2x}e^{ix}e^{2ix} [/itex]
then I combine everything so i get
[itex] e^{(2+3i)x} [/itex]
so then we integrate the exponential, so we divide by 2+3i
and then i multiply by the complex conjugate. now since sine is the imaginary part of his
formula I took the imaginary part when I back substituted for e^(3i)
but I didn't get the correct answer doing this, so am i not using Eulers formula correctly?
And then I use Eulers formula to substitute in for the sine terms.
So I have [itex] \int e^{2x}e^{ix}e^{2ix} [/itex]
then I combine everything so i get
[itex] e^{(2+3i)x} [/itex]
so then we integrate the exponential, so we divide by 2+3i
and then i multiply by the complex conjugate. now since sine is the imaginary part of his
formula I took the imaginary part when I back substituted for e^(3i)
but I didn't get the correct answer doing this, so am i not using Eulers formula correctly?