I'm struggling to integrate $\int \cos(2x)\cos(nx)\,\mathrm{ d}x$
I seem to be going round in circles and would be grateful if someone could help? I think I need to use a trig expansion or identity but I'm not sure which one?
Thanks =)
I'm struggling to integrate $\int \cos(2x)\cos(nx)\,\mathrm{ d}x$
I seem to be going round in circles and would be grateful if someone could help? I think I need to use a trig expansion or identity but I'm not sure which one?
Thanks =)