If #b^(-1/2) = 4#, what is the value of b?

1 Answer
Sep 4, 2015

You first rewrite the equation.

Explanation:

The #-# in a power means it is 1 divided by.
#1/2# as a power means #sqrt#

So #b^(-1/2)# means #1/sqrtb#

#1/sqrtb=4->4*sqrtb=1->sqrtb=1/4->#

Square both sides:
#sqrtb^2=(1/4)^2->b=1/16#

Check your answer by doing it the other way around:

#(1/16)^-1=1/(1/16)=16->#
#16^(1/2)=sqrt16=4#