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