ChatGPT calculus solver

How to find the limit

lim ⁡ x → ∞ [ ∫ 0 1 ( 1 + sin ⁡ π 2 t ) n d t ] 1 n \lim_{x \to \infty} \left [ \int_{0}^{1} \left ( 1+ \sin \frac{\pi }{2}t \right )^{n} \mathrm{d}t \right ] ^ \frac{1}{n} xlim[01(1+sin2pt)ndt]n1

According to the exchange rule of limit and integral, we can move the limit symbol into the integral symbol to get:

lim ⁡ n → ∞ [ ∫ 0 1 ( 1 + sin ⁡ π 2 t ) n d t ] 1 n = lim ⁡ n → ∞ [ ∫ 0 1 ( 1 + sin ⁡ π 2 t ) n d t ] 1 n   = exp ⁡ ( lim ⁡ n → ∞ ln ⁡ ( ∫ 0 1 ( 1 + sin ⁡ π 2 t ) n d t ) n )   = exp ⁡ ( lim ⁡ n → ∞ 1 n ln ⁡ [ 1 − cos ⁡ π 2 ( n + 1 ) π ( n + 1 ) + 2 π ] )   = exp ⁡ ( lim ⁡ n → ∞ ln ⁡ ( 1 − cos ⁡ π 2 ( n + 1 ) ) n + lim ⁡ n → ∞ ln ⁡ ( 2 π ( n + 1 ) ) n )   = exp ⁡ ( 0 + 0 )   = 1 . \begin{aligned} \lim_{n\to \infty}\left[\int_{0}^{1}\left(1+\sin\frac{\pi}{2}t\right)^n dt\right]^\frac{1}{n}&=\lim_{n\to\infty}\left[\int_{0}^{1}\left(1+\sin\frac{\pi}{2}t\right)^n dt\right]^{\frac{1}{n}}\ &=\exp\left(\lim_{n\to\infty}\frac{\ln\left(\int_{0}^{1}\left(1+\sin\frac{\pi}{2}t\right)^n dt\right)}{n}\right)\ &=\exp\left(\lim_{n\to\infty}\frac{1}{n}\ln\left[\frac{1-\cos\frac{\pi}{2}(n+1)}{\pi(n+1)}+\frac{2}{\pi}\right]\right)\ &=\exp\left(\lim_{n\to\infty}\frac{\ln\left(1-\cos\frac{\pi}{2}(n+1)\right)}{n}+\lim_{n\to\infty}\frac{\ln\left(\frac{2}{\pi(n+1)}\right)}{n}\right)\ &=\exp\left(0+0\right)\ &=\boxed{1}. \end{aligned} nlim[01(1+sin2pt)ndt]n1=nlim[01(1+sin2pt)ndt]n1 =exp nlimnln(01(1+sin2pt)ndt)  =exp(nlimn1ln[π ( n+1)1cos2p(n+1)+Pi2]) =exp nlimnln(1cos2p(n+1))+nlimnln(π ( n + 1 )2)  =exp(0+0) =1.

Among them, at the third equal sign, we use the integral formula ∫ 0 1 sin ⁡ n ( π / 2 t ) dt = 1 − cos ⁡ ( π / 2 ) ( n + 1 ) π ( n + 1 ) + 2 π \int_0^1 \sin^{n} (\pi/2 t) dt= \frac{1-\cos(\pi/2)(n+1)}{\pi(n+1)}+ \frac{2}{\pi}01sinn(π/2t)dt=π ( n + 1 )1 c o s ( π /2 ) ( n + 1 )+Pi2. At the last equal sign, we take advantage of when n → ∞ n\to \inftyn∞wave ,ln ⁡ ( 1 − cos ⁡ π 2 ( n + 1 ) ) n \frac{\ln\left(1-\cos\frac{\pi}{2}(n+1)\right)}{ n}nln(1cos2p(n+1)) ln ⁡ ( 2 π ( n + 1 ) ) n \frac{\ln\left(\frac{2}{\pi(n+1)}\right)}{n} nln(π ( n + 1 )2)The limits are all 0 00

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Origin blog.csdn.net/jiazhen/article/details/129571215