Question

what is the diffrence between sinA and sinC

Answer 1

for all real a ≠ 0. The normalization causes the definite integral of the function over the real numbers to equal 1 (whereas the same integral of the unnormalized sinc function has a value of π). ... The term sinc /ˈsɪŋk/ is a contraction of the function's full Latin name, the sinus cardinalis (cardinal sine).