Question

Ctan²a+sen²a+cos²a=csc²a

Answer 1

$ctg ^{2}a+ sen^{2}a+cos^{2}a=csc^{2}a \\ sabiendo.que.sen^{2}a+cos^{2}a=1 \\ ctg ^{2}a+ 1=csc^{2}a \\ sabiendo.que.ctga= \frac{cosa}{sena} \\ (\frac{cosa}{sena} )^{2} +1=csc^{2}a \\ \frac{cos^{2}a }{sen^{2}a } +1=csc^{2}a \\ \frac{cos^{2}a+sen^{2}a}{sen^{2}a} =csc ^{2}a \\ sabiendo.que.sen^{2}a+cos^{2}a=1 \\ \frac{1}{sen^{2}a}= csc^{2}a \\ sabiendo.que. \frac{1}{sena}=csca \\ csc ^{2}a= csc ^{2}a$

espero te sirva :)