91影视

The equation gives the intensity I on the screen, which is represented by the red line and is dependent on $胃$

$I=I_0{\left(\frac{\sin {\displaystyle }(蟺a\sin 胃/位)}{蟺a\sin 胃/位}\right)}^2$

The equation gives the minima, which are the points of destructive interference.

$\sin 胃=\frac{m位}{a}$

$\sin {胃}_{1m}=\frac{位}{a}=\frac{5.4脳{10}^{鈭�7}}{3.6脳{10}^{鈭�4}}=\frac{3}{2000}$

similarly, the angle is determined by the equation in the figure.

$\tan {胃}_{1m}=\frac{b}{x}$

As approximating the value;

$$\begin{gathered} b=x\tan {胃}_{1m} \\ =x\sin {胃}_{1m} \\ =1.2脳\frac{3}{2000}\mathrm{m} \\ =1.8\mathrm{mm} \end{gathered}$$

Hence, the distance on the screen from the center of the central maximum to the first minimum is 1.8mm

$\frac{1}{2}={\left(\frac{\sin {\displaystyle }纬}{纬}\right)}^2鈬�纬=\sqrt{2}\sin 纬$

Using the function f;

$f\left(纬\right)=\sqrt{2}\sin 纬$

From the graph, there are two fixed points, thus the sequence is;

$$\begin{gathered} {纬}_2=f\left({纬}_1\right) \\ ... \\ {纬}_n=f\left({纬}_{n-1}\right) \end{gathered}$$

By following;

$$\begin{gathered} lim{y}_n=y_0 \\ n鈫�鈭� \end{gathered}$$

So, the sufficient condition is;

$\left|f\text{'}\left({纬}_0\right)\right|<1$

As in the figure slope of f is smaller than that of the slope of identity (1),

So, the sequences are;

$$\begin{gathered} {纬}_2=\sqrt{2} \\ {纬}_3=1.397 \\ {纬}_4=1.393 \\ {纬}_5=1.392 \\ {纬}_0=\underset{n鈫�\mathrm{鈭�}}{lim}鈥�{纬}_n \\ =1.391557 \end{gathered}$$

From the definition;

${纬}_0=\frac{蟺a}{位}\sin {胃}_0鈬�\sin {胃}_0=\frac{位{纬}_0}{蟺a}$

So, the distance is;

$$\begin{gathered} b_{\frac{1}{2}}=x\tan {胃}_0 \\ =x\frac{{纬}_0}{蟺}\frac{位}{a} \\ =1.2\frac{1.391557}{蟺}\frac{3}{2000}\mathrm{m} \\ 鈮�0.8\mathrm{mm} \end{gathered}$$

Hence, the distance is 0.8mm.