Question

for y=sin nx
'n' is called the frequency.
what effect does 'n' have on the graph ??

Answer 1

for a graph from 0 to 2pi, there will be n complete periods of the sine curve.

The period of each sine curve will be 2pi/n

e.g. y = sin 4x will have 4 complete sine curves from 0º to 360º, and each sine curve will have a period of 90º
or
y = sin 4x will have 4 complete sine curves from 0 to 2pi, and each sine curve will have a period of pi/2