Calculating the Distance Between Interference Maxima: Yellow Light

[SEEDS]

Homework Statement

a)Yellow light Lambda= 589nm falls on a double slit. The distance between two slits is d=0.5 mm the width of each slit is a=100 micrometer. A screen showing the interference pattern is located 4 m behind the slits.

Homework Equations

What is the distance between the first and the second maximum on the screen ?

The Attempt at a Solution

To calculate the distance

tan theta1 = X1 / L
tan theta2 = X2/ L

X2 - X1 = is the answer ?

Is this right ? If it is , how can i calculate theta1 and theta2 ?
Thanks

 

[Redbelly98]

Where your textbook discusses the double slit there should be an equation, either for intensity as a function of angle OR the angles of the maxima (1st, 2nd, etc.)