Math Journal #2 and #3

1) Reflection for Qustion #7 pg 567

The question is: Consider the graph of the function with the equation y=2.

This is the lesson when we learned y=mx+b and the concept was pretty simple for me. Y= 2 means that the y-int equals 2 and that means that the line on a graph will be a horizontal line. In this question u had to state the values of m and b. Their so no slope so m=0 and I imputed the yint into b. Drawing the line on the graph was easy because it is just a straight line. I kind of got confused when they asked for the x int because on the graph the line does not go by x and then I realized that there is no x int. I remembered how to state the domain and range from the last unit. I learned from working on this question that using graph is a very good visual to help my learning.  I also learned to think outside the box. I think before the test I will need to study these types of questions and ask more questions about them. I will prepare myself by doing the practice test before the real test.

2) The x-intercept is where the function intercepts the x-axis. The y-intercept is where the function intercepts the y-axis.
When you look for the x-intercept given a equation, you set y = 0 then solve for x. Why is that?

You set y = 0 to find x because when y = 0 that means the line has to be going through x. When you solve for x you are isolating x and finding the x intercept, where the line is going through x on the graph. For example at the point (5,0) y = 0 and x = 5 and 5 is the x intercept.

Example: How do you find the x and y intercept for the equation :

y = \sqrt{x}-4 latex?

To find the x intercept you set y = 0 and solve for x. You plus 4 on both sides and then undo the sqrt by squaring the number. To find the y intercept you set x = 0 and solve for y which isolates the -4.

3) Reflection for Question #8 pg 605

This Question is: After 7 days of heavy rainstorms, the water level in a river peaked at 2.85 m above regular level. Four days later the water dropped to 2.25 m above the regular level.

This lesson we learned slope as a rate of change and it was one of the harder lessons for me. In the question the water was falling at a constant rate from the peak water level. For this question you needed to find a function that  describes the height of the river above regular level as a function of time. This means you needed to find the slope and create an equation of y = mx + b. Then you needed to figure out what the slope actually meant and this was easy for me because the water was just going down 0.15 m every day. I was confused when the question asked for the range and the domain. Then I realized that it was the peak water limit and when river has dried out. This question reminded me as the gas question because the amount kept on going down as time went on. I think I will have to study questions like this more before the test so that I completely understand them.

Math Journal

Question #3 pg. 479

The questions is Over the last 10 years, data was recorded for the number of cups of hot chocolate sold at the BGB Senior High School. It was found from the data that the water the day the less cups of hot chocolate were sold. The data can be modelled by the formula N t =150 – 10 t is the daily number of sups of hot chocolate sold the the average temperature is t C.

When I first read the problem I thought it was the same as all the other questions I had already anwnsered this assignment which it pretty much was but there was some different elements to it. To answer the questions you need to use the formula and input the (t). For this question you also need to be able to write the meaning of the function. When I was asked to explain the lower limit of the domain of the relation at first I was very confused. I thought it had to be a specific temperature but then I realized it was just the average minimum temperature. I learned when doing this question that all the questions may look  the same however their is different parts to them. I also learned to think outside the box. I think before the test I will need to study these types of questions and ask more questions about them. I will prepare myself by doing the practice test before the real test.