lim下面x→2(3x^2-2x+4) lim下面x→3 x-3/x^2-9 lim下面x→∞ 3x^2-2x+2/5x^2+5x+3懂的答

计算极限lim(lim下面是x→2)x^2-4/x^2-6x+8 lim x→∞(2x+1)/(3x-4) lim下面x→2(3x^2-2x+4) lim下面x→3 x-3/x^2-9 lim下面x→∞ 3x^2-2x+2/5x^2+5x+3懂的答 lim (x^3-x^2+4x)/(x^2+x) x→ 0 lim(x→∞)[(x^2-2x+1)/(x+1)直接化简即可：lim(x→∞)[(x^2-2x+1)/(x+1)]=lim(x→∞)[(x^2+x-3x-3+4)/(x+1)]=lim(x→∞)[x-3+4/(x+1)]我不知道下面这一步是怎么得来的:=lim(x→∞)[(x^2+x-3x-3+4)/(x+1)]=lim(x→∞)[x-3+4/(x+1)]x^ lim x(π/2-arctanx)＝?lim下面是+∞ 求极限lim(x→2)(x^2-3x+2)/(x^2+4x-12) lim x→1 (x^2-4x+3)/(x^4-4x^2+3) lim(x→∞)(4x^3+2x-1)/(2x^3-3x+1) lim(x→∞)(7x^3+4x)/(2x^3-x^2+3)=? lim (3x^2+4x+6)/(x^2+x) x→无限 lim(x→∞)(x^2+x)/(x^4-3x-1)的极限 lim(x→无穷)上面(3sinx+x^2cos1/x)下面(1+cosx)ln(x-1) lim(x+1)^x+1(x+3)^x+3/x^2x+4 x趋于无穷 帮忙`````````一些求极限的数学题一.求极限1.lim 3x^+2x+1x→12.lim x^+3x+2/x的三次方+4x^+5x→03.lim x^-1/x-1x→14.lim x^-3x+2/1-x^x→15.lim sin2x/5xx→06.lim sin3x/tan2xx→07.lim (1+x)的x分之2次方x→08.lim （1+2/n)的n次 f(X)是关于X的一个三次多项式.已知lim[f(x)/(x-2)]=lim[f(x)/(x-4)]=1x→2 x→4 求lim[f(x)/(x-3)]=?x→4 lim(1-2x)^(1/x)=?lim下面是X趋向于0 lim(x)lim(x→∞) [(x-1)/(x+1)]^2x 为什么 lim(x->∞) {[(-2)/(x+1)]*2x} = -4