Question

Find the value of c such that the point (2, 5) lies on the graph of
f(x) = cx^2 + 4x − 2.

c=????

Answer 1

Have you considered substituting the give values? x = 2, y = 5

Answer 2

Yes write it as
5=c(2)^2+4(2)-2 and then solve for c.

Answer 3

Would the answer be -5?

Answer 4

-1/4?

Answer 5

Let's find out!

\[f(x) = -5x^2+4x-2\]\[f(2) = 5 = -5(2)^2+4(2)-2\]\[5 = -5(4) + 4(2) - 2\]\[5 = -20 +8 -2\]Is that true?

Answer 6

Let's find out:
\[5 = -\frac{1}{4}(2)^2+4(2) - 2\]\[5 = -1+8-2\]\[5 = 5\checkmark\]

Answer 7

awesome! people are so helpful here

Answer 8

You should go back and figure out what mistake you made that made you think \(c=-5\)...
learn from your mistakes!