Single Slit Problems: 750nm Light & 2.0um Width

[Quantum Fizzics]

Homework Statement

At what angle will 750nm light produce a second minimum if the single-slit width is 2.0um

Homework Equations

Sin(theta)=n(lambda)/w

The Attempt at a Solution

This is what I got so far
(theta)=sin-1(3x10^-6/2x10^-6)

I don't understand why I keep getting error on my calculator, what am I doing wrong here please help

 

[Quantum Fizzics]

Homework Statement

At what angle will 750nm light produce a second minimum if the single-slit width is 2.0um

Homework Equations

Sin(theta)=n(lambda)/w

The Attempt at a Solution

This is what I got so far
(theta)=sin-1(3x10^-6/2x10^-6)
the answer btw is 49degrees

 

[haruspex]

I don't understand why I keep getting error on my calculator

It's because you are asking for an angle with sin > 1.
Where do you get 3x10^-6 from?