What are some clues that help us to determine whether an observed change is physical or chemical?

Who is available in a community to respond to the need of survivors of a traumatic event?

Transform the equation ${t(t - 1)y^{(4)} + e^{t}y'' + 4t^{2}y = 0}$ into an equivalent first order system.

Twelve students will be chosen at random from the 900 students at Rolling Meadows High School to serve as the Judicial Board for minor student infractions . (a) How many different Judicial Boards are possible? (b) Mariko hopes to be on the board. How many possible boards include her? (c) What is the probability (in percent) that Mariko is chosen for the board?

Assume that the flowrate. Q, of a gas from a smokestack is a function of the density of the ambient air,$\rho_{a}$, the density of the gas,$\rho_{g}$, within the stack, the acceleration of gravity, g, and the height and diameter of the stack, h and d, respectively. Use $\rho_{c}$, d, and g as repeating variables to develop a set of pi terms that could be used to describe this problem.

Two eighths of a circle equals what percent of a circle?

Solve the equation.

$$\ln (x-1)+\ln (x+1)=2 \ln \sqrt{12}$$

Solve the equation using square roots. $x^{2}-64=0$

Determine whether the function has an inverse (is one-to-one). If so, find the inverse and graph both the function and its inverse. $f(x)=x^{4}-2 x-1$

What role did the policy of containment play in the involvement of the United States in wars in Korea and Vietnam?

A soda can in the shape of a cylinder is to hold 16 fluid ounces. Find the dimensions of the can that minimize the surface area of the can.

Coloca las cosas antiguas en una columna y las modernas en la otra. (Put the words in the correct column.)

Consider two neighbouring lakes in an isolated region of Ontario. One lake is on limestone (calcium carbonate) while the other is lined with granite. Both receive the same amount of acid precipitation, (a) Explain why the limestone lake has a higher pH than the granite lake. (b) Which lake is likely to have a healthier aquatic ecosystem? Explain your answer.

The Hinge Theorem is also known as the Side-Angle-Side Inequality Theorem or SAS Inequality Theorem. How are the requirements for applying the Hinge Theorem similar to the requirements for applying SAS? How are the requirements different?