Indirect Variation

Q. If $y$ and $x$ are inversely proportional, then ($K$ is the constant of proportionality)

1. $y=Kx$
2. $xy=K$
3. $y=x$
4. $y=\frac{1}{x}$

Q.

Is $y=3x+1$ a direct variation?

Q. If $x$ and $y$ are inversely proportional, then $x\times y=K$ where $K$ is the constant of proportionality.

1. False
2. True

Q. For the equation $y=mx$, what is the constant of proportionality?

Q.

Which of the following equations is an example of inverse variation between the variables $x$ and $y$?

1. $y=\frac{x}{3}$

2. $y=\frac{3}{x}$

3. $y=x+3$

4. $y=3x$

Q. Are $x$ and $y$ inversely proportional?

1. Yes
2. No

Q. Identify the graph representing indirect variation.

1. 
2. 
3. 
4. 

Q. Does the equation $y=\frac{1}{7}x$ represent indirect variation?

1. Yes.
2. No.

Q.
Establish the relationship between x and y and find the constant of proportionality $k$.

1. $y\propto x,k=5$
2. $y\propto \frac{1}{x},k=6$
3. $y\propto x,k=6$
4. $y\propto \frac{1}{x},k=5$

Q. What is the value of the constant of proportionality for this distribution?

Q. What will be the equation to represent this graph?

1. $y=\frac{30}{x}$
2. $x\times y=15$
3. $x=\frac{y}{30}$
4. $y\times x=\frac{1}{30}$

Q. The volume V of a gas has an indirect variation with pressure P on it. If the volume is $120$ $c{m}^3$ under pressure of $23$ $\frac{kg}{c{m}^2}$, what pressure has to be applied to have a volume of $80c{m}^3$ ?

1. $34.5\frac{kg}{c{m}^2}$
2. $417.3\frac{kg}{c{m}^2}$
3. $54.5\frac{kg}{c{m}^2}$
4. $420.3\frac{kg}{c{m}^2}$

Q.

Is the equation $\mathrm{y}=-15\mathrm{x}$ a direct variation, if so what is the constant of variation?

Q.
If the speed ($y$) and the time ($x$) are inversely related, what is the speed of the car at $t=20$?

1. $y=4$km/h
2. $y=8$km/h
3. $y=12$km/h
4. $y=16$km/h

Q.

Assume that $y$ varies inversely as $x$, how do you write an inverse variation equation that relates $x$ and $y$ given $y=-4$ when $x=16$?