Question

Find the vertical and horizontal intercepts of the function f(x) = (x-1)(2x+1)

Answer 1

I got (-1, 0) for the vertical intercept but when I graph it on the calculator, the y-intercept is 1
y = (0-1)(2*0+1)
(-1)(1)=-1

Answer 2

The y-intercept is 0 on the calculator

Answer 3

y-intercept is when x = 0: y = (0-1)(0+1) = -1. (0,-1).
x-intercept is when y = 0: 0 = (x-1)(2x+1). x = 1 or -0.5. (-0.5,0) & (1,0).

Answer 4

Why would I get 0 on the calculator for the y-intercept?

Answer 5

I used 2nd and trace with the zero function

Answer 6

I don't have a calculator with that functionality and so I don't know what you entered wrong. But there must be some mistake. Perhaps did not make use of parenthesis correctly or something like that.

But the above answers are correct.

Answer 7

https://www.wolframalpha.com/input/?i=%28x-1%29%282x%2B1%29

Answer 8

Where does it show the intercepts on wolfram alpha?

Answer 9

Look at the first graph. It cuts the y-axis at -1 (vertical intercept) and the x axis at -0.5 and 1.0.

Answer 10

Yeah, I see it