Question

true or false.? true or false.? @Mathematics

Answer 1

or .... maybe

Answer 2

\[\int\limits_{-π}^{π}\cos(mx).\cos(nx).dx = π \delta _{mn}(1+\delta_{m0} )\]
where \[n,m \in \mathbb{N}\]

Answer 3

and please dont say maybe

Answer 4

whose delta function is that?

Answer 5

the cos product looks like it could be reduced to a trig identity at first glance

Answer 6

That is the Kronecker Delta function
ie δmn = 0 (m≠n),
= 1 (m=n)

Answer 7

cos(a+b) = cos(a)cos(b) - sin(a)sin(b)

but thats just random flashes of trig memory

Answer 8

im not familiar with that delta tho

Answer 9

\[πδ_{mn}(1+δ_{m0}) \] \[= π1(1+1)=2π\] when m=n=0
\[= π1(1+0)=π\] when m=n≠0

=π0 (1+0)
=0
when m≠n

Answer 10

so , t or f

Answer 11

?