Question

f(x)=-x^2(x+7)(x^2-1) find the x and y intercept

Answer 1

There are 5 x intercepts in this equation can you see any of them?

Answer 2

is the y intercept -7

Answer 3

You get the y intercept from setting x to zero, so
y = -(0)^2*(0-7)*(0^2-1)
So it would not be -7

Answer 4

To get the x intercepts you have to set y = 0 in each different multiplication factor making up the polynomial, so:
y = -x = 0
y = x = 0
y = x+7 = 0
y = x^2-1 = 0
You have to get x^2-1 into its factors
The solution to that would look like (x+?) * (x-?) this way the middle term is canceled out

Answer 5

for the x intercepts the function value =0

However it is already factorised for you so set each factor to 0 to get the solutions.

(HINT - there are only 4 discrete solutions)

Answer 6

http://www.mathsisfun.com/algebra/finding-intercepts-equation.html

so, you set y=0 to find the x-intercepts and solve for "x"
and x = 0 as shown above by Arfney and solve for "y"

Answer 7

@Arfney
I think you have a mistake (typo) in your post above:

-x^2=0
x+7=0
x^2-1=0

Answer 8

\(\large {
f(x)=-x^2(x+7)(x^2-1)
\\ \quad \\ \quad \\

y-intercept
\\ \quad \\
f(x)=y=-{\color{brown}{ 0}}^2({\color{brown}{ 0}}+7)({\color{brown}{ 0}}^2-1)
\\ \quad \\
x-intercept
\\ \quad \\
{\color{brown}{ 0}}=-x^2(x+7)(x^2-1)\to
\begin{cases}
0=x^2\\
0=x+7\\
0=x^2-1
\end{cases}
}\)