SOLUTION: can someone help me with this problem please Solve the inequality. x^2 - 1.01x - 83.19 < 0 (Give approximations rounded to the nearest hundredth.) a. (-infinity, -8.63) U

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Question 163052: can someone help me with this problem please
Solve the inequality.
x^2 - 1.01x - 83.19 < 0
(Give approximations rounded to the nearest hundredth.)
a. (-infinity, -8.63) U (9.64, infinity)
b. (9.64, -8.63)
c. (-infinity, -9.64) U (8.63, infinity)
d. (-9.64, 8.63)

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 - 1.01x - 83.19 < 0
Start with the equality x^2 - 1.01x - 83.19 = 0
x=-8.62982, x=9.63982 (quadratic formula)
These 2 numbers are inflection points.
We can select numbers below -8.7, between the 2 numbers and above 9.7 for x and see what sign y has.
x=-10 then x^2 - 1.01x - 83.19=26.91
x=0 then x^2 - 1.01x - 83.19=-83.91
x=10 then x^2 - 1.01x - 83.19=6.71
(-8.62, 9.64) Answer
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Ed
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graph%28500%2C500%2C-20%2C20%2C-100%2C100%2Cx%5E2-1.01x-83.19%29