Sun shades are sold in the shape of right isosceles triangles. If the equation represents one shade that shields 64 square feet of area, which system can be used to find the lengths of the legs of the sun shade?

A. [tex]\( \frac{1}{2} x^2 = 64 \)[/tex]

B. [tex]\( y = \frac{1}{2} x^2 + 64 \)[/tex] and [tex]\( y = 0 \)[/tex]

C. [tex]\( y = \frac{1}{2} x^2 \)[/tex] and [tex]\( y = 64 \)[/tex]

D. [tex]\( y = \frac{1}{2} x^2 + 64 \)[/tex] and [tex]\( y = \frac{1}{2} x^2 - 64 \)[/tex]



Answer :

To determine which system can be used to find the lengths of the legs of the sun shade, let's analyze each option step-by-step.

Given the equation:
[tex]\[ \frac{1}{2} x^2 = 64 \][/tex]

We need to check each system of equations provided to see which one matches this given equation.

Option 1:
[tex]\[ y = \frac{1}{2} x^2 + 64 \][/tex]
and
[tex]\[ y = 0 \][/tex]

- Substituting [tex]\(y = 0\)[/tex] into the first equation:
[tex]\[ 0 = \frac{1}{2} x^2 + 64 \][/tex]
[tex]\[ \frac{1}{2} x^2 = -64 \][/tex]

This results in:
[tex]\[ x^2 = -128 \][/tex]

This is not correct since the right-hand side should be 64, not -64.

Option 2:
[tex]\[ y = \frac{1}{2} x^2 \][/tex]
and
[tex]\[ y = 64 \][/tex]

- Substituting [tex]\(y = 64\)[/tex] into the first equation:
[tex]\[ 64 = \frac{1}{2} x^2 \][/tex]
Solving for [tex]\(x^2\)[/tex]:
[tex]\[ \frac{1}{2} x^2 = 64 \][/tex]

This directly matches the given equation:
[tex]\[ x^2 = 128 \][/tex]

Thus, [tex]\(x\)[/tex] will lead us to the lengths of the legs of the sun shade when solved correctly.

Option 3:
[tex]\[ y = \frac{1}{2} x^2 + 64 \][/tex]
and
[tex]\[ y = \frac{1}{2} x^2 - 64 \][/tex]

- These two equations represent different and additional terms, as follows:
1. [tex]\(y = \frac{1}{2} x^2 + 64\)[/tex]
2. [tex]\(y = \frac{1}{2} x^2 - 64\)[/tex]

Setting these equal would result in:
[tex]\[ \frac{1}{2} x^2 + 64 = \frac{1}{2} x^2 - 64 \][/tex]
[tex]\[ 64 = -64 \][/tex]

This is a contradiction and does not match the given equation.

From the analysis, Option 2,
[tex]\[ y = \frac{1}{2} x^2 \][/tex]
and
[tex]\[ y = 64 \][/tex]

is the correct system that can be used to find the lengths of the legs of the sun shade.