I am very new to this and my teacher has asked us to write compile and run a program that calculates the fourth square root of 81. using the sqrt function. am so lost please help!!!!!

Are you really sure you need help with that?

Just ask yourself what a fourth square root is...

it's the value that when multiplied by itself four times makes the total
i.e.
x * x * x * x = y

So what does the sqrt() function do?
it takes the second square of a number, i.e.
x * x = y

That means that if we apply that to y i.e.

a = sqrt(y)

a would be the number that makes up the second square root

if we insert y=81 we would get 9, since 9x9=81
now if we break down 9 in it's square root, we get 3, since 3x3 = 9
hence 3x3 x 3x3 = 81

so...

X = sqrt(sqrt(Y));

thank you so much that makes perfect sense now my teacher is from Taiwan and is very difficult to understand and his handwriting is much worse than mine sometimes soaking in what he is trying to teach is very difficult