# Thread: Please help: My Concept on following are not clear

1. ## Please help: My Concept on following are not clear

1. Kc = 4 √(4s+1)
What is the domain of the function defined by this equation? what restrictions do nature put on S?

2. Write the equation of the line passing through (-1, 1) with undefined slope.

3. The percentage P of high school seniors who have tried cigarettes can be described by:
P= 75.4509 – 0.706948t
Where t is the number of years past 1975.

a. Write a sentence which interprets slope
b. Here, what does P-intercept means?
c. What is the annual rate of change of percent?

2. Originally Posted by itsnayyer
1. Kc = 4 √(4s+1)
What is the domain of the function defined by this equation? what restrictions do nature put on S?

2. Write the equation of the line passing through (-1, 1) with undefined slope.

3. The percentage P of high school seniors who have tried cigarettes can be described by:
P= 75.4509 – 0.706948t
Where t is the number of years past 1975.

a. Write a sentence which interprets slope
b. Here, what does P-intercept means?
c. What is the annual rate of change of percent?
1. What can't you have underneath the square root sign? Start with finding the domain of: $\sqrt{x}$ and apply this to your problem.

2. Slope is rise/run or $\frac{\bigtriangleup y}{\bigtriangleup x}$. that is change in y over change in x. For this to be undefined $\bigtriangleup x$ must be zero. And if you have no change in x then you get a ________ line. Therefore the line passing through (-1,1) which has an undefind slope is _=__

3.(a) Notice you have an equation in the form f(x)=y=mx+b. In this form 'm' is the slope. Relate this to your problem.
(b) How can you get the P intercept in your equation. What does t equal when this occurs? What does t mean?......
(c) annual rate of change is, for example, going from year one to year two, or year 34 to year 35. Find the change in P. $\bigtriangleup P = P_{final} - P_{initial}$

Furthermore, you really should post your work so we can see where you are stuck. Most of the time you will not receive help if you do not.

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