1) Найти производную y = 1 / arccos^2x

Arccos (x) '=-1 / (√ (1-x²)

arccos² (x) '=-2*arccos (x) / √ (1-x²)

1/arccos² (x) = (1'*arccos² (x) - 1*arccos² (x) ') / arccos⁴ (x) =

= (0 - (-2*arccos (x) / √ (1-x²)) / arccos⁴ (x) = 2*arccos (x) / (arccos⁴ (x) * √ (1-x²)).