2. у'=(sin⁴(eˣ/4))'=4sin³((eˣ/4))*cos(eˣ/4))*(eˣ/4)
4. x'=(1/2√(1-t²))*(3*(1-t²)²)2t
y'=1/√(1-t²)
y'ₓ=(1/√(1-t²))/((1/2√(1-t²))*(3*(1-t²)²)2t)
y'ₓ=1/t*(1-t²)
