Determine the value(s) of k for which the graph of y=2x^2+kx+8 does not intersect the x axis. How about if the graph is to intersect the x axis at exactly one point.?
im can't seem to solve this problem
im can't seem to solve this problem
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Arrange the equation so that it takes the form
y - a = m * (x - b) ^ 2
where a and b are expressions involving k
Then the /minimum/ value that (y - a) can ever have is zero. (Why is that?)
So, if a is greater than zero, y can never be negative and the graph will not intersect the x axis.
If a is exactly zero, the graph will touch the x axis at exactly one point
y - a = m * (x - b) ^ 2
where a and b are expressions involving k
Then the /minimum/ value that (y - a) can ever have is zero. (Why is that?)
So, if a is greater than zero, y can never be negative and the graph will not intersect the x axis.
If a is exactly zero, the graph will touch the x axis at exactly one point