Question

Mode cosx=cosx-2sinx

Answer 1

Integration from π to 0 cos(x)dx

∫from 0 to π mod of cos (x) dx=0, a0≠0a0≠0 because

∫π/20 |cos(x)| dx=∫from π to π/2|cos(x)|dx

∫from 0 to π/2 |cos(x)|dx=∫π to /2π|cos(x)|dx

We can evaluate it as follows, as can be seen in the plot below

a0=1/π∫from π to – π |cos(x)| dx

2/π∫from π to 0 |cos(x)| dx

4/π∫π/20|cos(x)|dx

4/π∫π/20cos(x)dx

4/π

It will go further with the submission of the n from 1 to infinity (-1^n-1/1-4n^2 = ½ -pie/4

Put it in the cosx – 2 sinx value to get the solution.