Question

integration of cosmx* cosnx ,lim π yends to -π​

Answer 1

Step-by-step explanation:

cosmx*cosnx dx= 1/2(2cosmx*cosnx) dx

=1/2[cos(mx+nx)+cos(mx-nx)]dx

=1/2[-sin(mx+nx)-sin(mx-nx)]

=-1/2[sin(mx+nx)+sin(mx-nx)]