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lim(1/(x+1)﹣3/(x^3+1))x趋向于﹣1求极限哦亲..lim(1/(x+1)﹣3/(x^3+1))x趋向于﹣1求极限哦亲

题目详情
lim(1/(x+1)﹣3/(x^3+1) ) x趋向于﹣1 求极限哦亲 ..
lim(1/(x+1)﹣3/(x^3+1) ) x趋向于﹣1 求极限哦亲
▼优质解答
答案和解析
原式=lim(x->-1)[1/(x+1)-3/((x+1)(x²-x+1))]
=lim(x->-1)[(x²-x-2)/((x+1)(x²-x+1))]
=lim(x->-1)[((x-2)(x+1))/((x+1)(x²-x+1))]
=lim(x->-1)[(x-2)/(x²-x+1)]
=(-1-2)/(1-(-1)+1)
=-1.