Question

Решите пожалуйста!номер 1

Answer 1

sin²x + cos²x = 1
1 + ctg²x = 1/cos²x
ctg²x = 1/cos²x - 1
ctg²x =[ 82/(9√82])² - 1
ctg²x = 82/81 - 1
ctg² = 1/81
1)  ctgx = - 1/9
x₁ = arcctg(-1/9) + πn, n∈Z
2)  ctgx = 1/9
x₂ = arcctg(1/9) + πn, n∈Z