Racing cyclists use the function r(x)=4 sqrt x to determine the maximum rate,r(x) , in miles per hour, to turn a corner of radius x, in feet, without tipping over. What is the maximum rate a cyclist should travel around a corner of radius 18 feet without tipping over? Leave the solution in simplified radical form.

a. 16 sqrt 2 mph
b. 16 + sqrt 2 mph
c. 4(4+ sqrt 2) / r mph
d. 12 sqrt 2 mph

Question

Racing cyclists use the function r(x)=4 sqrt x  to determine the maximum rate,r(x) , in miles per hour, to turn a corner of radius x, in feet, without tipping over. What is the maximum rate a cyclist should travel around a corner of radius 18 feet without tipping over? Leave the solution in simplified radical form.

a. 16 sqrt 2 mph
b. 16 + sqrt 2 mph
c. 4(4+ sqrt 2) / r mph
d. 12 sqrt 2 mph

apoorvk · Answer

plug in x=18 in the equation. simple enough. what do you think?

jlastino · Answer

A follow up, you can simplify a square root of something by expressing it as a product of two numbers

jlastino · Answer

d. 12 sqrt 2 mph

apoorvk · Answer

hmm yeah D.