Identify Function and Point: Identify the function and the point at which we need to find the limit.We are given the function f(x)=x+1x4+2x3+x2 and we need to find the limit as x approaches −1.
Check Indeterminate Form: Check if direct substitution of x=−1 into the function yields an indeterminate form.f(−1)=((−1)4+2(−1)3+(−1)2)/(−1+1)=(1−2+1)/0=0/0This is an indeterminate form, so we cannot simply substitute x=−1 to find the limit.
Factor Numerator: Factor the numerator to simplify the expression.The numerator is a polynomial that can be factored by grouping.x4+2x3+x2=x2(x2+2x+1)Notice that x2+2x+1 is a perfect square trinomial and can be factored further.x2(x2+2x+1)=x2(x+1)2
Cancel Common Factor: Cancel out the common factor from the numerator and the denominator.The common factor is (x+1), which can be canceled out.f(x)=(x+1)x2(x+1)2After canceling out (x+1), we get:f(x)=x2(x+1)
Substitute and Find Limit: Substitute x=−1 into the simplified function to find the limit.f(−1)=(−1)2(−1+1)=1(0)=0