we are asked to determine the equation of a parabola given three points. To do that let's remember the general form of a quadratic equation in vertex form:
![y=a(x-h)^2+k](https://img.qammunity.org/2023/formulas/mathematics/college/97p0xsjs0cwme4ddvwkim2cbbqprhnlhsv.png)
Where the point (h, k) is the vertex. We are given that:
![(h,k)=(4,-2)](https://img.qammunity.org/2023/formulas/mathematics/college/36pz9h8fs1hsdc4v5eert414n3t0q66a3n.png)
Replacing in the equation we get:
![y=a(x-4)^2-2](https://img.qammunity.org/2023/formulas/mathematics/college/cfwb1rpdrx5g5bkvu6ix3zd1s3qflbbw2o.png)
Now, to determine the value of "a" we use the point (2, 0). Replacing we get:
![0=a(2-4)^2-2](https://img.qammunity.org/2023/formulas/mathematics/college/sjdgnw4t1mqf6lutblzd0zajvuw2amcy48.png)
Solving the operations:
![0=4a-2](https://img.qammunity.org/2023/formulas/mathematics/college/jz1x7ft2gbigpdz82yp0eq0bejecopmxct.png)
Now we solve form "a" first by adding 2 to both sides:
![\begin{gathered} 2=4a \\ (2)/(4)=a \\ (1)/(2)=a \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/m54djtyld5fhxb4cidma8qhc3b9gxr67td.png)
Replacing the value of "a" in the equation:
![y=(1)/(2)(x-4)^2-2](https://img.qammunity.org/2023/formulas/mathematics/college/7w05x6byz2a3j1x4pk91pakk3u0dw0cu8x.png)
Now the y-intercept is the point where x = 0. replacing that value of "x" in the equation we get:
![y=(1)/(2)(0-4)^2-2](https://img.qammunity.org/2023/formulas/mathematics/college/e77dw521y3dbrgsi16lp0x5pku65ey6zh6.png)
Solving the operations:
![\begin{gathered} y=(1)/(2)(16)-2 \\ y=8-2=6 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/kxnl6jgh8j6scri2v0by41hv1rofe0b931.png)
Therefore, the y*