Answer:
see explanation
Step-by-step explanation:
Consider the left side
1 + cot²A
= 1 + [tex]\frac{cos^2A}{sin^2A}[/tex]
= [tex]\frac{sin^2A+cos^2A}{sin^2A}[/tex]
= [tex]\frac{1}{sin^2A}[/tex]
= cosec²A
= right side, thus proven
