SOLUTION: Graph the quadratic function. Indicate the x-intercepts, y-intercepts, domain, range, axis of symmetry, vertex, and maximum or minimum of the function. F(x)=-2x(to the 2nd power)+8

Algebra ->  Pythagorean-theorem -> SOLUTION: Graph the quadratic function. Indicate the x-intercepts, y-intercepts, domain, range, axis of symmetry, vertex, and maximum or minimum of the function. F(x)=-2x(to the 2nd power)+8      Log On


   



Question 964268: Graph the quadratic function. Indicate the x-intercepts, y-intercepts, domain, range, axis of symmetry, vertex, and maximum or minimum of the function. F(x)=-2x(to the 2nd power)+8x-13
Answer by lwsshak3(11628) About Me  (Show Source):
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Graph the quadratic function. Indicate the x-intercepts, y-intercepts, domain, range, axis of symmetry, vertex, and maximum or minimum of the function. F(x)=-2x(to the 2nd power)+8x-13
***
f(x)=2x^2+8x-13
complete the square:
f(x)=2(x^2+4x+4)-8-13
f(x)=2(x+2)^2-21
..
x-intercepts
set y=0
2x^2+8x-13=0
use quadratic formula to solve to solve for x:
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a=2, b=8, c=-13
ans:
x=-5.24
or
x=1.24
..
y-intercepts
set x=0
y=-13
..
domain: (-∞, ∞) (all real numbers)
range: (-21, ∞)
axis of symmetry: x=2
vertex: (-2, -21)
minimum: -21
..
see graph below:
+graph%28+300%2C+200%2C+-6%2C+5%2C+-30%2C+10%2C+2x%5E2%2B8x-13%29+