Consider the following for the next three (03) items that follow :

Let $I_1=\int_0^\pi \frac{x}{1+\cos ^2 x} d x$ and 

$I_2=\int_0^\pi \frac{1}{1+\sin ^2 x} d x $

What is the value of $\frac{I_1+I_2}{I_1-I_2} $ ?

Consider the following for the next three (03) items that follow :

Let $I_1=\int_0^\pi \frac{x}{1+\cos ^2 x} d x$ and 

$I_2=\int_0^\pi \frac{1}{1+\sin ^2 x} d x $

What is the value of $8 I_1^2$

Consider the following for the next three (03) items that follow :

Let $I_1=\int_0^\pi \frac{x}{1+\cos ^2 x} d x$ and 

$I_2=\int_0^\pi \frac{1}{1+\sin ^2 x} d x $

What is the value of I₂ ?

Consider the following for the next two (02) items that follow :

Let $l=\int_a^b \frac{|x|}{x} d x, $ a < b

What is l equal to when a < 0 < b ?