Answer
$\frac{I_3}{I_0} = cos^4~30^{\circ}$
$A = 1$
$n = 4$
$\theta = 30^{\circ}$
Work Step by Step
We can write an expression for $I_1$:
$I_1 = I_0~cos^2~30^{\circ}$
We can write an expression for $I_2$:
$I_2 = I_1$
$I_2 = I_0~cos^2~30^{\circ}$
We can write an expression for $I_3$:
$I_3 = I_2~cos^2~30^{\circ}$
$I_3 = (I_0~cos^2~30^{\circ})~cos^2~30^{\circ}$
$\frac{I_3}{I_0} = cos^4~30^{\circ}$
$A = 1$
$n = 4$
$\theta = 30^{\circ}$
