Lim 3x / tan3x x 0如何解决?我认为答案将是1或-1谁能解决它?
限制为1. Lim_(x - > 0)(3x)/(tan3x)= Lim_(x - > 0)(3x)/((sin3x)/(cos3x))= Lim_(x - > 0)(3xcos3x )/(sin3x)= Lim_(x - > 0)(3x)/(sin3x).cos3x = Lim_(x - > 0)颜色(红色)((3x)/(sin3x))。cos3x = Lim_(x - > 0)cos3x = Lim_(x - > 0)cos(3 * 0)= Cos(0)= 1请记住:Lim_(x - > 0)颜色(红色)((3x)/(sin3x))= 1和Lim_(x - > 0)颜色(红色)((sin3x)/(3x))= 1
Lim _ {n to infty} sum _ {i = 1} ^ n frac {3} {n} [( frac {i} {n})^ 2 + 1] ...... ...?
4 = lim_ {n-> oo}(3 / n ^ 3)[sum_ {i = 1} ^ {i = n} i ^ 2] +(3 / n)[sum_ {i = 1} ^ {i = n} 1]“(Faulhaber公式)”= lim_ {n-> oo}(3 / n ^ 3)[(n(n + 1)(2n + 1))/ 6] +(3 / n)[n ] = lim_ {n-> oo}(3 / n ^ 3)[n ^ 3/3 + n ^ 2/2 + n / 6] +(3 / n)[n] = lim_ {n-> oo} [1 +((3/2))/ n +((1/2))/ n ^ 2 + 3] = lim_ {n-> oo} [1 + 0 + 0 + 3] = 4
Lim(e ^ x + x)^(1 / x)为x 0 +?
Lim_(x-> 0 ^ +)(e ^ x + x)^(1 / x)= e ^ 2 lim_(x-> 0 ^ +)(e ^ x + x)^(1 / x)(e ^ x + x)^(1 / x)= e ^(ln(e ^ x + x)^(1 / x))= e ^(ln(e ^ x + x)/ x)lim_(x-> 0 ^ +)LN(E ^ X + X)/ X = _(DLH)^((0/0))lim_(X-> 0 ^ +)((LN(E ^ X + X))')/ ((x)')= lim_(x-> 0 ^ +)(e ^ x + 1)/(e ^ x + x)= 2因此,lim_(x-> 0 ^ +)(e ^ x + x )^(1 / x)= lim_(x-> 0 ^ +)e ^(ln(e ^ x + x)/ x)=设置ln(e ^ x + x)/ x = u x-> 0 ^ + u-> 2 = lim_(u-> 2)e ^ u = e ^ 2