Answer:
a. csc²θ
Step-by-step explanation:
You can use the identities ...
1 +tan² = sec²
cot = cos/sin
sec = 1/cos
csc = 1/sin
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Then the expression becomes ...
[tex]\cot^2{\theta}(1+\tan^2{\theta})=\cot^2{\theta}\sec^2{\theta}=\dfrac{\cos^2{\theta}}{\sin^2{\theta}\cos^2{\theta}}=\dfrac{1}{\sin^2{\theta}}\\\\=\boxed{\csc^2{\theta}}[/tex]
