Draw the temperature-time graph in each of the following cases:
|Time (in hours):||7:00||9:00||11:00||13:00||15:00||17:00||19:00||21:00|
|Temperature (°F) in:||100||101||104||102||100||99||100||98|
Here, time is an independent variable and temperature is a dependent variable. So, we take time on the x-axis and temperature on the y-axis.
Let us choose the following scale:
For point (i):
On x-axis: 1 cm = 1 hours
On y-axis: 1 cm = 2οF
For point (ii):
On x-axis: 2 cm = 2 hours
On y-axis: 1 cm = 1οF
Let us assume that on the x-axis, the coordinate of origin is 6:00.
On y-axis, the coordinate of origin is 94οF .
So, the coordinates of O are (6:00, 94).
Now, let us plot (7:00, 100), (9:00, 101), (11:00, 104),..(21:00, 98) for point (i) and (8:00, 100), (10:00, 101), (12:00, 104),...,(20:00, 100) for point (ii). These points are joined to get the graphs representing the given information as shown in the figures below.