It is very important to look at the graph very minutely. It can be seen that at 30 minutes the slope is a little more than negative 50 and at <span>90 minutes it is a little less than negative 50. From this fact, it can be deduced that the estimated rate of </span><span>change of the temperature after an hour would be -50/60. I hope that the answer has come to your desired help.</span>
5 = c. infinite.
6 = I don't know. sorry!!
Hope this helps!!
First, find slope of point A and B using slope formula:
<u>y2-y1</u> = <u>7-0 </u>= <u>-7</u>
x2-x1 3-8 5
Next, use the point-slope formula to find the equation (pick either point A or B to substitute into this equation; the answer will be the same either way):
y-y1=m(x-x1)
y-7=<u>-7</u>(x-3) (I used point B here)
5
y=<u>-7x</u> +<u>56</u> so the y-intercept is <u>56</u>. Hurray! Part 1 down!
<span> 5 5 5
Now to answer part 2. Since AB ll CD, they have the same slope: <u>-7</u>
5
Therefore, you can use the handy point-slope equation to calculate the equation of line CD. (Remember you only need one of the points to use this equation if you already have the slope.) Since the only point given is D(5,5), we'll use that one:
</span>y-y1=m(x-x1)
y-5=<u>-7</u>(x-5)
<span> 5
</span>y=<u>-7x</u> + 12 Yay! That's the answer to part 2; the equation of line CD
<span> 5</span>
4.3125 is the answer to that equation
