SOLUTION: after 2 minutes on a treadmill jenny has a heart raete of 84. after 3 minutes she has a heart rate of 86. assume that there is a linear equation that gives her heart rate h in the

Algebra ->  Linear-equations -> SOLUTION: after 2 minutes on a treadmill jenny has a heart raete of 84. after 3 minutes she has a heart rate of 86. assume that there is a linear equation that gives her heart rate h in the      Log On


   



Question 70228: after 2 minutes on a treadmill jenny has a heart raete of 84. after 3 minutes she has a heart rate of 86. assume that there is a linear equation that gives her heart rate h in the terms of time on the treadmill t. Find the equation and use it to find her heart rate after 10 minutes on the treadmill
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
One approach to solving this problem is to treat the given input data, ie, heart-rate and time, as the coordinates of points on a graph. Instead of the usual (x, y) you can use (t, h) where t is time and h is heart rate.
With the two given points you can find the slope of this linear relationship using:
m+=+%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 or rather: m+=+%28h%5B2%5D-h%5B1%5D%29%2F%28t%5B2%5D-t%5B1%5D%29
Once you have found the slope, you can start writing the equation in the slope-intercept form (h = mt+b) which will be just perfect for this problem.
Let's find the slope using the two given point (t, h) which are: (2, 84) and (3, 86)
m+=+%2886-84%29%2F%283-2%29
m+=+2%2F1
m+=+2
You can now write the start of the equation as:
h+=+2t%2Bb where b is the h-intercept. Substitute the t- and h-coordinates from either one of the two given points and solve for b. Using (2, 84) we get:
84+=+2%282%29%2Bb Simplify and solve for b.
b+=+80
Now you can write the final equation for this linear relationship:
h+=+2t%2B80
To find Jenny's heart rate (h) after 10 minutes (t=10) on the treadmill, make the appropriate substitutions into your final equation and solve for h.
h+=+2%2810%29%2B80
h+=+20%2B80
h+=+100
Jenny's heart rate will be 100 bpm after 10 minutes on the treadmill.