? QUESTION The number of bacteria in a culture decreases according to a continuous exponential decay model. The initial population in a study is 400 bacteria, and there are 140 bacteria left after 6 minutes. (a) Let \( t \) be the time (in minutes) since the beginning of the study, and let \( y \) be the number of bacteria at time \( t \). Write a formula relating \( y \) to \( t \). Use exact expressions to fill in the missing parts of the formula. Do not use approximations. \( y=\square \)

What is the magnitude of a vector with a horizontal component of 5 and a vertical component of \( 12 ? \)

Select your answer What is the direction of a vector with a horizontal component of -2 and a vertical component of -4 ? \( -63^{\circ} \) \( -117^{\circ} \) 0.

Argumen dari \( 1-i \sqrt{3} \) adalah...

The number of U.S. travelers to other countries during the period from 1990 through 2009 can be modeled by the polynomial function \( P(x)=-0.00530 x^{3}+0.1366 x^{2}+1.250 x+46.49 \) where \( x=0 \) represents \( 1990, x=1 \) represents 1991 , and so on and \( P(x) \) is in millions. Use this function to approximate the number of \( U \).S. travelers to other countries in each given year. (a) 1990 (b) 2000 (c) 2009 (a) In 1990 , the number of U.S. travelers to other countries was approximately \( \square \) million. (Simplify your answer. Type an integer or decimal rounded to the nearest tenth as needed.) (b) In 2000, the number of U.S. travelers to other countries was approximately \( \square \) million. (Simplify your answer. Type an integer or decimal rounded to the nearest tenth as needed.) (c) In 2009, the number of U.S. travelers to other countries was approximately \( \square \) million. (Simplify your answer. Type an integer or decimal rounded to the nearest tenth as needed.)

Determine the implied domain of the following function. Express your answer in interval notation. \[ f(x)=\sqrt{x}-9 \] Answer