college algebra, Please help!!
posted by ladybug .
Answer the following function.
A. Is the point (-2,9) on the graph of f?
B. If x equals 2, what is fx? What point(S) are on the graph of f?
c. if f(x)= -1, what is x? what point(s) are on the graph of f?
d. what is the domain of f?
e. List the x-intercpts, if any, of the graph of f.
f. List the y-intercept if any, of the graph of f.
**Can someone please help me with this. I have no idea, i'm lost!!!
A. is f(-2) = 9? if it is, then the point (-2,9) is on the graph. Otherwise, it's not on the graph
B.Plug 2 into f(x)
f(2) = 2 * (2^2) - 2 - 1
The points on this graph are (2, f(2))
-1 = 2*x^2-x-1
You should find two solutions for x.
D. The domain of f is the range of values for x for which f(x) is real. In this case, the domain is -infinity to infinity
E. Find the solutions when x = 0:
2*0^2 - 0 - 1 = f(x=0)
F. Find the solutions when f(x) = 0
0 = 2*x^2 -x - 1
Solve for the two values of x that make this equation true