Wednesday

March 4, 2015

March 4, 2015

Posted by **Eric** on Friday, March 22, 2013 at 5:02pm.

Express f(x) in the form a(x − h)2 + k.

f(x) = −4x2 + 24x − 9

Find the standard equation of a parabola that has a vertical axis and satisfies the given conditions.

vertex (0, −7), passing through (3, 38)

Thank You!

- Algebra -
**Reiny**, Friday, March 22, 2013 at 5:11pmfor the first, complete the square:

f(x) = -4(x^2 - 6x ......) - 9

= -4( x^2 - 6x + 9 -9) - 9

= -4( (x-3)^2 - 9) - 9

= -4(x-3)^2 + 36 - 9

= -4(x-3)^2 + 27

for the second, you know the vertex is (0,-7)

so f(x) = a(x-0)^2 - 7

= ax^2 - 7

but (3,38) lies on it, so

38 = a(9)

a = 38/9

f(x) = (38/9)x^2 -7

- Algebra -
**Steve**, Friday, March 22, 2013 at 5:11pmf(x) = -4(x^2-6x) - 9

= -4(x^2-6x+9) -4(-9) - 9

= -4(x-3)^2 + 27

f(x) = a(x-0)^2 - 7

38 = 9a-7

a = 5

f(x) = 5x^2 - 7

- go with Steve's end # Algebra -
**Reiny**, Friday, March 22, 2013 at 5:13pmdon't know where my - 7 went ????

- Algebra -
**Eric**, Friday, March 22, 2013 at 5:20pmThank You Guys!!!

**Answer this Question**

**Related Questions**

biology - Given the part of the molecule shown below, can the underlined atom ...

calculus - Find an equation for the surface consisting of all points P(x, y, z) ...

algebra - Find the standard form for the equation of a circle (x−h)^2+(y...

physics - Four charges −8 × 10^−9 C at (0 m, 0 m), −7 × 10^&#...

Grade 12 Calculus - Evaluate each of the following. Show all your calculations...

math - The number 27+200−−−√−−−−...

calculus (gr 12) - Evaluate each of the following. Show all your calculations. a...

calculus (gr 12) - Evaluate each of the following. Show all your calculations. a...

Math - First, give the technology formula for the given function and then use ...

algebra - Which of the following is equivalent to the expression (t2 − t...