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High School Teacher
Factor `x^3+3x^2+5x+15` :
Factor two terms at a time:
Now (x+3) is a common factor of both remaining terms and can be factored out:
`x^2+5` does not factor in the reals -- it can be fully factored in the complex numbers:
Posted by embizze on May 23, 2013 at 12:36 AM (Answer #2)
The equation can be factored as follows:
0x^2+5x + 15
5x + 15
There exists one real root at x=-3
a=3; b=6; c=5
b^2-4ac = 36-4(3)(5)=-24<0
Therefore there are no maximum or minimum points.
f''(x)=6x+6=0 -> x=-1
f''(0)=6>0 -> concave up for x>-1
f''(-2)=-6<0 -> concave down for x<-1
Therefore there is an inflection point at x=-1 where the graph changes from concave downwards to concave upwards
Posted by crmhaske on May 22, 2013 at 10:06 PM (Answer #1)
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