Imaginary zeros of polynomials

Now Playing:Imaginary zeros of polynomials– Example 1

Discussing the Relationship Between the Discriminant and X-intercepts on a Graph
Sketch and compare the following quadratic functions:
i)
$y=2{x^2} + x - 15$
ii)
$y=x^2+4x+4$
iii)
$y=2{x^2} + x + 15$
Locating the Regions of Imaginary Zeros on Polynomial Graphs
Indicate the region on the graphs where the non-real zeros occur.
i) $f\left( x \right) = \frac{1}{{10}}\left( {x + 2} \right)\left( {x - 1} \right)\left( {x - 3} \right)\left( {x - 5} \right)$
ii) $g\left( x \right) = \frac{1}{{10}}\left( {x + 2} \right)\left( {x - 1} \right)\left( {{x^2} - 8x + 17} \right)$