\(R_1nt\left(R_2//R_3\right)\Rightarrow R_N=R_1+\dfrac{R_2R_3}{R_2+R_3}\)

\(\Rightarrow I=\dfrac{\varepsilon}{r+R_N}=\dfrac{\varepsilon}{r+R_1+\dfrac{R_2R_3}{R_2+R_3}}=...\left(A\right)\)

\(\Rightarrow U_{23}=U_2=U_3=I.R_{23}=I.\dfrac{R_2R_3}{R_2+R_3}=...\left(V\right)\)

\(\Rightarrow I_3=\dfrac{U_3}{R_3}=...\left(A\right)\)

c/ \(H=\dfrac{U_N}{\varepsilon}=\dfrac{I.\left(R_1+\dfrac{R_2R_3}{R_2+R_3}\right)}{\varepsilon}=...\%\)

\(A=\dfrac{hc}{\lambda_{kem}}=3,55.1,6.10^{-19}\Rightarrow\lambda_{kem}\approx0,35\left(\mu m\right)\)

\(\lambda_{tim}\in\left[0,38-0,44\right]>\lambda_{kem}\)

=> Khong xay ra hien tuong uang dien

22/ \(\omega A=8\pi\)

\(A^2=x^2+\dfrac{v^2}{\omega^2}\Leftrightarrow A^2=3,2^2+\dfrac{\left(4,8\pi\right)^2}{\omega^2}\)

\(\Leftrightarrow\omega^2A^2=3,2^2\omega^2+23,04\pi^2\Leftrightarrow64\pi^2=3,2^2.\omega^2+23,04\pi^2\Leftrightarrow\omega=2\pi\left(rad/s\right)\)

\(\Rightarrow f=\dfrac{\omega}{2\pi}=\dfrac{2\pi}{2\pi}=1\left(Hz\right)\Rightarrow D.1Hz\)

23/ \(\omega A=20;\omega^2A=80\Rightarrow\left\{{}\begin{matrix}\omega=4\left(rad/s\right)\\A=5cm\end{matrix}\right.\)

\(\Rightarrow v=\omega\sqrt{A^2-x^2}=4.\sqrt{5^2-4^2}=12\left(cm/s\right)\Rightarrow A.12cm/s\)

Bài viết rất hay và bổ ích ạ! Em cũng đang luyện đọc hiểu nên rất mong cô sẽ đăng nhiều bài như vầy :3

\(y=x^3-3x^2+2x+2\Rightarrow y'=3x^2-6x+2\)

Vi \(\Delta\perp d:y=x-3\Rightarrow y'=-1\Leftrightarrow3x^2-6x+2=-1\)

\(\Rightarrow x=1\Rightarrow y=1-3+2+2=2\)

\(\Rightarrow\Delta:y=-1\left(x-1\right)+2\)