2.2.48 Derivatives and differentials
Condition: Find the derivatives of the functions: 1) \( y=x \operatorname{arccot}^{2}(3 x) \), 2) \( y=\cos \left(x^{4+9 x}\right) \)
Calculation of derivatives and differentials of first and higher orders of functions of one and many variables, including partial derivatives.