# x intercepts

• February 24th 2009, 06:47 PM
andru21
x intercepts
1. a vegetable garden with an area of 200 square ft is to be fertiliezed. If the lenght of the garden is 1 foot less than three times the width, find the dimension of the garden?

2. Find the X-intercepts
F(x)=X^2/18 + X/2 + 1

Need this ASAP thanks so much
• February 24th 2009, 08:22 PM
ixo
1. If A=lw and you know A=200ft then find what l and/or w are:
"the length of the garden is 1 foot less than three times the width"
l=(3w-1)
so now you know A and L (in terms of w). Now you just combine the equation and solve for w using A=(l)w. Then you use the width you just found and solve for length and your done.

2. Is the question:
$f(x)=\frac{x^2}{18} + \frac{x}{2} + 1$

Regardless of your current equation, X intercepts are when the function crosses the X axis which means y=0 at those points. Solve the equation accordingly.

example find the x intercepts of
$f(x)=x^2 + 4$ just solve for: $x^2 + 4=0$

$(x-2)(x+2)=0$ which means that $(x-2)=0$ And $(x+2)=0$
then solve the equations. So the x intercepts are x=2 bc when x=2 y=0 and x=-2 bc when x=-2 y also equals zero
• February 24th 2009, 09:13 PM
Quote:

Originally Posted by andru21
1. a vegetable garden with an area of 200 square ft is to be fertiliezed. If the lenght of the garden is 1 foot less than three times the width, find the dimension of the garden?

2. Find the X-intercepts
F(x)=X^2/18 + X/2 + 1

Need this ASAP thanks so much

(1) Let length =L and width=W

2L+2W=3W-1 -----------1
LW=200 -----------2

Solve the system .

(2) X-intercepts only occur when y or f(x) = 0