A diffraction grating with $700$ lines$/$mm is illuminated with light of wavelength $650$ nm$.$ A very

wide viewing screen is $2\mathrm{.}00$ m from the grating.

a$)$ What is the linear distance between the zero$-$ and first$-$order diffraction maxima on the screen?

BE CAREFUL: Is the small angle approximation valid in this problem?

b$)$ What is the maximum number of bright fringes that could be observed