Re: Help with calculus problem with logarithm base e!
I'm not quite sure I understand... Why does 2ex times 2ex equal 4e2x?
And also, If I weren't to factorise I would continue with
4e2x-2ex=0
4e2x=2ex
Is it incorrect to simplify this to
2e2x=ex
And if so, why?
I'm at one of those annoying stages where you know what the answer is, but you just can't seem to prove it... Would really appreciate some help with this one!
The question is:
What are the intervals where function f(x)=e2x-2ex is concave and convex respectively.
I have derived f(x) to get...
My answer is wrong according to the book, but I don't see where my mistake was made..
The question:
The temperature of a steak that's being put into the oven can be describe with
T(x) = 175-153e-kx
where T(x) is the temperature in degrees Celsius t minutes after the steak has been put into the...
I've solved half the question (I think), but then gotten stuck... Can someone help me out?
The question:
The tangent to the curve y=ae2x + bx on the point (0,4) has the gradient k=3. Determine the values of a and b.
My solution:
y' = 2ae2x+b
y'(0) = 3
2ae2(0)+b)=3
2a+b=3
b=3-2a
And this is...
In a tea shop one mixes two different kinds of tea to get a new flavor. One of the kinds costs 135kr/kg, the other costs 168kr/kg. How large amounts of each kind have you taken if the mixture costs 150kr/kg?
I tried setting up this equation system:
135x + 168y = 150
x+y=1
but I don't think it...
A pipe with a circular cross-section area has the inner diameter of 28 mm. How big should the pipe's outer diameter be, if the cross section area of the pipe's wall is 4.5 cm2?
I have been trying to solve this for ages, but failed so far... Can someone help?
I need help with understanding two questions:
1. (2x+2)2
The answer I got was: 22x+2x++4, but according to the answers that is wrong. Can any explain why?
2. 84x/32x
I simplified this to become (84/32)x, but I don't know how to go from there... The answer is apparently 27x, but I don't...
The number of bacteria in a culture is given by B(t) = 40e0.6t, where t is the time in days.
How many bacteria are there after 2 days?
I substituted t = 2, and got this:
2B = 40e1.2
which I simplified to become this
B = 66.4 days
Apparently this answer is wrong though, can someone explain why?