Choose the best description of the roots of the equation 3x2 - 4x + 5 = 0.
Double root
Real and rational roots
Real and irrational roots
Imaginary roots
Solution:
The standard form of the quadratic equation ax2 + bx + c = 0 and the formula used is
x = [-b ± √(b2 - 4ac)]/ 2a
It is given that
3x2 - 4x + 5 = 0
Here a = 3, b = -4 and c = 5
Substituting these values in the formula
x = [-(-4) ± √((-4)2 - 4 × 3 × 5)]/ (2 × 3)
By further simplification
x = [4 ± √(16 - 60)]/6
x = [4 ± √-44]/ 6
So we get,
x = [4 ± 2√-11]/ 6
x = [2 ± i √11]/ 3
Also the discriminant is b2 - 4ac = -44 < 0. Thus we have imaginary roots.
Therefore, the best description of the roots of the equation 3x2 - 4x + 5 = 0 is imaginary roots.
Choose the best description of the roots of the equation 3x2 - 4x + 5 = 0.
Summary:
The best description of the roots of the equation 3x2 - 4x + 5 = 0 is imaginary roots.
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