a.) kx^2-6x+1=0 if the equation has real, rational, and equal
roots.
If the function has rational , real and equal roots, then
that mean delta will be 0:
We know
that:
delta = b^2 - 4ac
==>
delta = (-6)^2 - 4*k*1
==> 36 - 4k =
0
==> -4k = -36
==> k =
-36/-4 = 9
==> k = 9
b.) 2x^2+6x+k=0 find the smallest integral value of
k, such that the equation had imaginary roots
If the function has
imaginary of (complex) roots, then delta should be less than 0 (
negative).
==> delta = b^2 -
4ac
==> delta = (6^2) - 4*2*k <
0
==> 36 - 8k <
0
==> -8k <
-36
==> k >
-36/-8
==> k > 9/2
Then
the smallest integer is the first integer that comes after 9/2
9/2 =
4.5 , then the next integer s 5
Then k = 5 is the
smallest integer so the equation has complex roots.
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