3.4․13 Tangents and normals
Condition: Find the angles between the intersecting curves \( y=f(x) \) and \( y=\varphi(x) \), having previously deduced the general formula. \( f(x)=x(x+1), \varphi(x)=2 x \).
Solving problems in three-dimensional space using tangents and normals, both straight lines and planes.