Question
y is proportional to x^n.
Write down the value of n when
(a) y cm^2 is the area of a circle of radius x cm
(b) y hours is the time taken to travel a distance x km at a constant speed
Answer for (a) Answer for (b)
y =k x^n ----------------------- (1) y =k x^n ----------------------- (1)
A = (pi) r^2 Time = Distance/Speed
Since are A = y, radius r = x Since Time = y and Distance = x
So, y = (pi) x^2 -------------- (2) So, y = x^1/Speed ------------ (2)
By comparing the power of x in (1) & (2) By comparing the power of x in (1) & (2)
n = 2 n = 1