Unsure of what you mean by "reference number."
I do recognize that 11pi/9 is in quadrant III. I suspect that the so-called "reference number" is the acute angle between the end ray of 11pi/9 and pi, or, in more easily comparable numbers, between 9pi/9 and 11pi/9.
That difference is 2pi/9.
The equation is y=mx+b, m being the slope of the line and b being the y-intercept.
Short answer: - 1
The first thing you should do is draw this or get a program to do it. I use desmos. It is included. The graph shows one complete cycle every 2*pi intervals (or 360 degrees.)
You will find no lower value that y = - 1 (nor any value greater than y = 1)
Answer:
W = 6t + 90
Step-by-step explanation:
Given :
Starting weight = intercept = 90 kg
Weight gained after 8 months = 138 kg
Using the slope intercept relation ;
We can obtain the rate of change, slope ;
y = mt + c
m = slope ; t = time after t months ; c = intercept
y = weight gained after 8 months
138 = 8m + 90
138 - 90 = 8m
48 = 8m
m = 48 / 8
m = 6
Hence, slope intercept equation equals :
W = 6t + 90