Which expression is equivalent to (x^1/4y^16)^1/2 ?

expression is equivalent to  

We apply exponential property

Multiply the outside exponent 1/2 with exponents inside the parenthesis

1/4 times 1/2 is 1/8  

16 times 1/2 is 8

so expression becomes

So the answer is

for this case we have that by definition, the volume of a cylinder is given by:

where:

r: it's the radio

h: it's the height

we have as data that:

substituting:

so, the cylinder volume is

option d