Question

Henry is designing a model for a dome shaped glasshouse. He creates the model and records the horizontal distance from the edge of the greenhouse of the dome over its vertical height from the base of the model. The table shows the horizontal distance from the edge of the greenhosue, in inches, x, over its verital height from the base, in inches, f(x). Use data in table to create standard form of the function that models this situation.

Answer 1

Explanation:

Answer 2

Correct choice is B

Explanation:

All given options represent quadratic function. Let the equation of this quadratic function be

`f(x)=ax^2+bx+c.`

Then

1.
`f(0)=2=a\cdot 0^2+b\cdot 0+c\Rightarrow c=2;`

2.
`f(1)=7.5=a\cdot 1^2+b\cdot 1+c\Rightarrow 7.5=a+b+2;`

3.
`f(2)=12=a\cdot 2^2+b\cdot 2+c\Rightarrow 12=4a+2b+2.`

Solve the system of two equations:

`\left\{\begin{array}{l}a+b+2=7.5\\4a+2b+2=12\end{array}\right.\Rightarrow\left\{\begin{array}{l}a=5.5-b\\4(5.5-b)+2b=10\end{array}\right.`

Then

`22-4b+2b=10,\\ \\-2b=-12,\\ \\b=6,\\ \\a=5.5-6=-0.5.`

Thus, the equation of the function is

`f(x)=-(1)/(2)x^2+6x+2.`

Note that

`f(3)=-(1)/(2)\cdot 3^2+6\cdot 3+2=-4.5+20=15.5;`

`f(4)=-(1)/(2)\cdot 4^2+6\cdot 4+2=18.`