ответ:f(x)=x²+x+1, x₀=1
1. y=y(x₀)+y'(x₀)*(x-x₀)
2.y(x₀)=y(1)=1+1+1=3
3. y'(x)=(x²+x+1)'=2x+1
4. y'(x₀)=y'(1)=3
5. y=3+3*(x-1)
y=3x
