A little help

[NotaPhysicsMan]

Hey, another question I'm working on.

How many dark fringes will be produced on either side of the central maximum if light, (651nm) is incident on a single slit that is 5.47 x 10^-m wide?

Ok, I figure I could use this forumula sin@= m x lambda/Width. Am I trying to locate the maximum m (the order of the dark fringe) that it'll go?

I tried solving for m=1 and got a angle of 6.83 degrees. Now where to?
Any tips/hints welcome.

Thanks.

[Gokul43201]

What do you know about the range of values of sin@ ?

[NotaPhysicsMan]

I missed something, the W is suppose to be 5.47x10^-6 m. Well, I know it can't go past 90 degrees and the min is the central max, which is 0 degrees.

[NotaPhysicsMan]

So if I put sin90=m x lambda/W and solve for m, then I'll get 8.40? so 8 dark fringes?

[NotaPhysicsMan]

can someone verify please and thanks