[問題]天山 09-27

[GMAT]

If f is the function defined for all k by f(k)=k^5/16,what is f(2k) in terms of f(k)?

A.1/8 f(k)
B.5/8 f(k)
C.2 f(k)
D.10 f(k)
E.32f(k)

答案:E

請問這題怎算?

[clbb]

直接把2k帶到公式中==>f(2k)=(2k)^5/16

=(2^5*k^5)/16

=2^5(k^5/16)

=32(k^5/16)

=32f(k)

[GMAT]

直接把2k帶到公式中==>f(2k)=(2k)^5/16

=(2^5*k^5)/16

=2^5(k^5/16)

=32(k^5/16)

=32f(k)

Thank you!