38 Calcola la distanza tra due corde parallele di una circonferenza situate dalla stessa parte rispetto al centro sapendo che sono lunghe rispettivamente misura 65 cm .

Schreiben Sie 0.0042 in wissenschaftlicher Notation.

Use the elimination method to find a general solution for the given linear system, where differentiation is with respect to \( t \). \( x^{\prime}=5 x-6 y+\sin t \) \( y^{\prime}=3 x-y-\cos t \) Eliminate \( x \) and solve the remaining differential equation for \( y \). Choose the correct answer below. A. \( y(t)=C_{1} e^{2 t}+C_{2} t e^{2 t}+\frac{19}{40} \cos t+\frac{7}{40} \sin t \) B. \( y(t)=C_{1} e^{-2 t} \cos 3 t+C_{2} e^{-2 t} \sin 3 t+\frac{19}{40} \cos t+\frac{7}{40} \sin t \) C. \( y(t)=C_{1} e^{-2 t}+C_{2} t e^{-2 t}+\frac{19}{40} \cos t+\frac{7}{40} \sin t \) D. \( y(t)=C_{1} e^{2 t} \cos 3 t+C_{2} e^{2 t} \sin 3 t+\frac{19}{40} \cos t+\frac{7}{40} \sin t \) E. The system is degenerate.

Solve the system of equations by the substitution method: \( \left\{\begin{array}{l}5 x+4 y=47 \\ x=3 y-2\end{array}\right. \) Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. The solution is \( \square \). (Simplify your answer. Type an ordered pair.) B. There are infinitely many solutions; \( \{(x, y) \mid 5 x+4 y=47\} \) or \( \{(x, y) \mid x=3 y-2\} \). There is no solution; \( \} \) or \( \varnothing \).

Solve the following system of equations. \[ \begin{aligned} 4 x-2 y+3 z=-1 \\ 4 y+z=7 \\ 4 x+2 y+4 z=4\end{aligned} \] Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. A. There is one solution. The solution is ( (Type integers or simplified fractions.) B. There are infinitely many solutions. The solution set is \( \{(x, y, z) \mid 4 x+2 y+4 z=4\} \). O. The solution set is \( \varnothing \).

he widespread use of insecticides has (A) reduced the number of wild animals (B) caused imbalance in the relationship between living beings and their environment (C) eliminated diseases by killing mosquitoes and flies () caused biological hazards