Question

Find the number of real roots of the equation:
f(x)=x^3+2x^2+2x+1=0

Answer 1

f(x)=x^3+2x^2+2x+1
Put x=-1
f(-1)=-1^3+2(-1)^2+2(-1)+1
f(-1)=-1+2-2+1
f(-1)=0

Hence,-1 is the real root of f(x)}