SOLUTION: Please help me solve this equation Let f(x) = 2x^2 − 8x − 7. (a) Write the quadratic in vertex form (that is y = a(x − h)^2 + k for some constants a, h, and

Algebra ->  Equations -> SOLUTION: Please help me solve this equation Let f(x) = 2x^2 − 8x − 7. (a) Write the quadratic in vertex form (that is y = a(x − h)^2 + k for some constants a, h, and       Log On


   

Question 1078497: Please help me solve this equation
Let f(x) = 2x^2 − 8x − 7.
(a) Write the quadratic in vertex form (that is y = a(x − h)^2 + k for some constants a, h, and k).
(b) Calculate the roots of the function f.
(c) Sketch the graph of f, showing all important features. (Vertex, roots, y intercept.)
(d) Solve f(x) > 0.
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!

---( reworked)---

Starting from the given function,
f%28x%29=2%28x%5E2-4x%29-7
2%28x%5E2-4x%2B4-4%29-7
2%28%28x-2%29%5E2-4%29-7
2%28x-2%29%5E2-8-7
highlight%28f%28x%29=2%28x-2%29%5E2-15%29


ROOTS
2%28x-2%29%5E2-15=0
2%28x-2%29%5E2=15
%28x-2%29%5E2=15%2F2
x-2=0%2B-+sqrt%2815%2F2%29
x=2%2B-+sqrt%2815%2F2%29
highlight%28x=2%2B-+sqrt%2830%29%2F2%29



--------------------------------------------------
a%28x%5E2-2hx%2Bh%5E2%29%2Bk
cross%28ax%5E2-2ahx%2Bh%5E2%2Bk%29
ax%5E2-2ahx%2Bah%5E2%2Bk
-
system%28a=2%2C-8=-2ah%2C-7=ah%5E2%2Bk%29

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Please help me solve this equation
Let f(x) = 2x^2 − 8x − 7.
(a) Write the quadratic in vertex form (that is y = a(x − h)^2 + k for some constants a, h, and k).
(b) Calculate the roots of the function f.
(c) Sketch the graph of f, showing all important features. (Vertex, roots, y intercept.)
(d) Solve f(x) > 0.
FYI The other person's answers are WRONG, NONSENSICAL, and should be IGNORED. 

The correct answer for a) is: highlight_green%28f%28x%29+=+2%28x+-+2%29%5E2+-+15%29%29

You have to try to figure out the rest on your own, but whatever you do, IGNORE the other person's RIDICULOUS answers.