The dose-response for a specific drug isf

(

x

)

=

100

x

2

x

2

+

0.39

f(x)=100x2x2+0.39

, wheref

(

x

)

f(x)

is the percent of relief obtained from a dose ofx

x

grams of a drug, where0

x

1.5

0x1.5

.

Findf

'

(

0.5

)

f(0.5)

and select the appropriate units.