Answer:
see explanation
Step-by-step explanation:
Using the Pythagorean identity
sin²α + cos²α = 1 ( divide each term by sin²α )
[tex]\frac{sin^2\alpha }{sin^2\alpha }[/tex] + [tex]\frac{cos^2\alpha }{sin^2\alpha }[/tex] = [tex]\frac{1}{sin^2\alpha }[/tex] , that is
1 + cot²α = cosec²α ← as required
