How many y-intercepts does the graph of the parabola x = y^2 - 4y - 1 have?

Guest Oct 9, 2019

#1**+1 **

2 y-intercepts

https://www.desmos.com/calculator/buaqjswt7y

This is because the equation forms an ellipse, and is in the ellipse form.

CalculatorUser Oct 9, 2019

#2**+2 **

You're close, CU......this actually is a * parabola* that opens to the right

We can find the y intercepts by setting x = 0 and solving

y^2 - 4y - 1 = 0

y^2 - 4y = 1 complete the square on y

y^2 - 4y + 4 = 1 + 4

(y - 2)^2 = 5 take both roots

y - 2 = ±√5

y = 2 ±√5

So.....there are two y intercepts as shown by CU's graph....!!!!

CPhill Oct 9, 2019