Solve 2x2 + 3x + 5 = 0. Round solutions to the nearest hundredth I got -4.75 and -1.25
need to make sure I solved correctly
\[ 2x^2 + 3x + 5 = 0\\ b^2 -4 a c=3^2 -4(2)(5)=9 -40=-31\\ \] So the two roots are complex.
\[ \begin{array}{c} x=\frac{1}{4} \left(-3-i \sqrt{31}\right) \\ x=\frac{1}{4} \left(-3+i \sqrt{31}\right) \\ \end{array} \]
So there is no real solution?
No
Did you type your problem correctly?
2x^2+3x+5=0
May be they want you to write the roots as \[ \begin{array}{c} x=-0.75-1.39194 i \\ x=-0.75+1.39194 i \\ \end{array} \]
To the nearest hundredth \[ \begin{array}{c} x=-0.75-1.39 i \\ x=-0.75+1.39 i \\ \end{array} \]
Are you still there?
Yes I'm just confused as to how you got that answer
Use the quadratic formula and your Calculator.
Oh I did +4ac instead of -4ac
A big difference.
I'm getting a -31 and you can't square - numbers
?
\[ \sqrt{-31} = i \sqrt{31} \]
Where \[ i^2 = -1 \]
What does that mean?
Do you know how to use the quadratic formula? Do you know what a complex number is?
quadratic formula , yes complex number, no
For quadratic formula, you need to know complex numbers in case b^2 - 4 ac <0
Okay and what if you do have a complex number?
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