Mathematics
Grade10
Easy
Question
Suppose y varies inversely as the square of x. If x is multiplied by 4 , which of the following is true for the value of y?
- It is multiplied by 4
- It is multiplied by 16
- It is multiplied by
- It is multiplied by
Hint:
Mathematical relationship between two variables which can be expressed by an equation in which the product of two variables is equal to a constant.
The correct answer is: It is multiplied by
We have to find the value of y when y varies inversely to the square of x.
We have, y = 
If x becomes 4x, then:
y = 
= 
So, y is multiplied by .
Hence, the correct option is D.
Instead of taking y= k/x², we could also have taken yx² = k, where k is a constant.
