mtcmath said:Can you please help me to work this problem: solve and graph:
5x^2 - 10x + 26
Solve and graph: .\(\displaystyle y \:=\:5x^2 - 10x + 26\)
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* | *
* | *
* | *
(0,26)o o(2,26)
| o
| (1,21)
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- - - - + - - + - - - - - - - - -
| 1
v: (--10/2(5), f(x)= 1)
5(1)^2 - 10(1) + 26
5 - 10 + 26 = 21
If you are looking for x-intercept - your calculations are correct (except as indicated above)Code:5x^2 - 10x + 26 = x = --10+/- (square root: (-10)^2-4(5)(26) _________________________________ 2(5) x= 10 +/- 2 i (square root: 105) _______________________ 10 = 1 +/- i [(square root: 105)]/5 [/quote]
This function (graph) does not cross x-axis - as evidenced by i in the expressions for roots.
Remember:mtcmath said:thank you, and one last question please, when you have a negative square root, how do you know to have the i on the outside or inside the square root, such as: the square root of ?-28, would it be written as 2?7i or 2i?7