What work have you done so far?
Can somebody help me find the stationary points of this:
\displaystyle{Q(x) = \frac{4x^2 + 20x + 25}{e^x}}
and if the above doesnt display right it is:
4x^2+20x+25/e^x
and give the value of the points?
Also say whether points are a local max or min and explain why to me?
Thank you in advance!
You need to be more careful with your parentheses. Technically, you wrote
-4x^2-12x-(5/e^2).
Also, I think you forgot the 2x in the exponent. Anyway, aside from notation issues, I think you have the general idea:
What now? How do you find stationary points?
e^2x on the bottom? are you sure?
Well you have to find out which values make the equation equal zero after the first derivative I'm fairly certain.
Then you put that point back into the equation to see what value you get for that point.
THEN get the second derivative and and judging by what THAT point is you can tell if you have a local max or min....
but I def need some help lol
Quotient rule: low dee high minus high dee low over the square of what's below, ore^2x on the bottom? are you sure?
Since you have an in the denominator of the original fraction, you'd better have an in the denominator afterwards, right? You're not going to lose the variable x, at any rate.
So what do you get when you set the derivative equal to zero?
You are correct in forgetting about the denominator, since it will never contribute towards a zero. However, you are not solving the quadratic correctly.
You cannot assume that if ab = c, where c is not zero, that a=c, or b=c. Just take 2 x 3 = 6. It is not true that 2 = 6 or 3 = 6.
Complete the square, or use the quadratic formula. What do you get?