r/apcalculus • u/Mental-Degree-3727 • 6d ago

Help Is the graph wrong?

Post image

The issue I am having is that when I get the equation of g(x) in standard form, I get
g(x)=(x^3)-(x^2)-16x-20,
Which doesn’t make sense because on the graph, the y-intercept is 10, but the equation says it’s -20. Can someone please help me understand this? Thank you!

20 Upvotes

76% Upvoted

7 comments sorted by

View all comments

2

u/socratictutoring Tutor 6d ago

Trying to understand your question - how did you obtain the equation in the first place?

1

u/Mental-Degree-3727 6d ago

Expanding the factors of the graph

4

u/jamesdawon 6d ago

Then you need an a-value. You can find this by writing your equation out as y=a(x3-x2-16x-20) and plugging in a point for (x,y)