What’s the correct answer for this?

Write the equation for the parabola that has x− intercepts (−2,0) and (4,0) and y− intercept (0,4).

Find the domain of the following expression: 1/(√x)-2

Lin is writing an equation to model the proportional relationship between y, the total cost in dollars of downloading videos from a website, and x, the number of videos downloaded. she knows that the total cost to download 3 videos was $12. her work to find the equation is shown below. joylin’s work step 1 k= 3/12= 0.25 step 2 y= 0.25x where did joylin make her first error?