Answer:
how you convert feet to square feet
length X width = square feet
if the board is 3ft long and 1 foot wide
3ft X 1ft = 3square feet
so the length is 3 feet
Recall the Maclaurin expansion for cos(x), valid for all real x :

Then replacing x with √5 x (I'm assuming you mean √5 times x, and not √(5x)) gives

The first 3 terms of the series are

and the general n-th term is as shown in the series.
In case you did mean cos(√(5x)), we would instead end up with

which amounts to replacing the x with √x in the expansion of cos(√5 x) :

Answer:
imm didn't understand , what link
0.2 since it is not a fraction.
Answer:
no entiendo nada eso es inglés y pus yo no lo entendo