the question is "express the total number S of square feet of glass needed as a function of x"...the aquarium in the picture has a height of 1.5, a length of x, and a width of y.
this is what i did:
2(lw +hl+hw)
this is what i got to:
3x+2xy+3y
how would i get y by itself, in order to make this a function of x?
2007-08-26 06:42:36 · 4 answers · asked by UNCBballGirl 2 in Science & Mathematics ➔ Mathematics
the book says the answer is S(x)=4+3x+(12/x)
how did they get that?
2007-08-26 06:52:19 · update #1
S(x) just means it's a function.
it's not another variable.
2007-08-26 07:51:29 · update #2
get the x on the other side
so that u end up with 2 y things on the left side
then factor out the y
and divide by the additive
sooo
2xy+3y=s-3x
y(2x+3)-s-3x
divide by 2x+3
y=(s-3x)/(2x+3)
:-)
wait... are aquariums always covered on all sides... mine isnt on the top.... so maybe tat will change the eqns we came up with...
2007-08-26 06:48:36 · answer #1 · answered by DSS 1 · 1⤊ 1⤋
S = x*y + 3*x* + 3*y
This is as far as you can go without additional information. DSS, your equation simplifies to "1 = 1" which doesn't solve anything.
You have 1 equation, 3 unknowns (S,x,y). The best you can hope to come up with is a function in terms of two variables, ie S(x,y).
And unless you're missing something big, the book's answer is completely wrong. Just try x=y=0, surface area should be zero, book's answer is 4.
2007-08-26 14:35:59 · answer #2 · answered by MooseBoys 6 · 0⤊ 0⤋
S is a function of both x and y.
You cannot express it as a function of x unless y is a constant or y is some function of x.
2007-08-26 14:04:53 · answer #3 · answered by ironduke8159 7 · 0⤊ 0⤋
You need to have one more constraint such that you can link y to x.
2007-08-26 13:48:02 · answer #4 · answered by sahsjing 7 · 0⤊ 0⤋