GATE 2014-EC 4

Question

Let f(x,y)=xⁿy^m =P

If x is doubled and y is halved, the new value of f is

(A) 2^n-m P   (B) 2^m-n P   (C) 2(n-m) P    (D) 2(m-n) P

Answer 1

f(x,y) = $x^{n} y^{m} = p$

x is doubled and y is havled

f(2x,$\frac{y}{2}$) = $( 2x)^{n} (\frac{y}{2})^{m}$ = $2^{n} 2^{-m}x^{n}y^{m} =2^{n-m} P$

 

Hence, Option (A) $2^{n-m} P$ is the correct choice.