Question

Use the image to answer the question.

A coordinate plane reveals a curve.
▶Click for Long Desc

Rhianna graphed a square root function. What is the equation of the function she graphed?

(1 point)
Responses

y=2x−4−−−−−√

y equals 2 Start Root x minus 4 End Root

y=12x+4−−−−−√

y equals Start Fraction 1 over 2 End Fraction Start Root x plus 4 End Root

y=2x+4−−−−−√

y equals 2 Start Root x plus 4 End Root

y=12x−4−−−−−√

Answer 1

I can’t see the image you mentioned. Could you either upload it here or tell me two clear points on the curve (one is usually the starting point where the square root begins, and one other point)? With those I can pick the correct equation.

How to tell which equation it is (so you can check quickly):
- A square-root function has form y = a·√(x − h) where (h,0) is the leftmost/start point (horizontal shift). If the start point is (4,0) use (x−4); if it’s (−4,0) use (x+4).
- The vertical stretch/compression a is found from any other plotted point (x1,y1): a = y1 / √(x1 − h).

So:
- If the start point is (4,0) the candidates are y = 2√(x−4) or y = (1/2)√(x−4).
- If the start point is (−4,0) the candidates are y = 2√(x+4) or y = (1/2)√(x+4).

Give me the start point and one other point (for example (5,2) or (8,4)) and I’ll identify the equation.