Recent content by Dank2
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Undergrad Exponential equation with logs
Answers are x=0, x=-1. Anyone have a clue how to show it ? it doesn't have to be a proof.- Dank2
- Post #5
- Forum: General Math
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Undergrad Exponential equation with logs
dont mind the t=0, since it cannot be.- Dank2
- Post #4
- Forum: General Math
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Undergrad Exponential equation with logs
You mean write down 25 as 10log1025?- Dank2
- Post #3
- Forum: General Math
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Undergrad Exponential equation with logs
How can i continue from here, answer is x=0,-2- Dank2
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- Exponential
- Replies: 5
- Forum: General Math
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Undergrad Geometry question with a triangle
Thanks, solved using cosine for the two triangles- Dank2
- Post #5
- Forum: General Math
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Undergrad Geometry question with a triangle
AB=AC. P is on ac such that AP=3PC. Q on CB such that CQ=3BQ. Need to find the length of PQ. I know i can use the Cosine theorem, but the answer is without Cosine.- Dank2
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- Geometry Triangle
- Replies: 9
- Forum: General Math
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Number of functions from a to b where {123} is in the range of (f)
Homework Statement A has n elements. B={0,1,2,3} {1,2,3}⊆range(f) Homework EquationsThe Attempt at a Solution So in each function we must choose those 3 numbers in the range. So let's first choose all the diffrent possiblites to choose those 3: n*(n-1)*(n-2) now for the remaining elemnts, we...- Dank2
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- Functions Range
- Replies: 1
- Forum: Precalculus Mathematics Homework Help
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Proof by Induction: Proving n=i=0n∑ ai2i
I'm assuming it's true for ##n##. but by subtracting greater power of ##2k## that is less than ##n+1##, how do i get to ##n##? since ##n-####2^k## > ##1## for example if ##n =10, k=3##. ##n+1-2^3=3##.- Dank2
- Post #4
- Forum: Precalculus Mathematics Homework Help
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Proof by Induction: Proving n=i=0n∑ ai2i
<Moderator's note: Moved from a technical forum and thus no template.> for every natural n there exists natural k. and numbers={a0,a1,a2,...ak}∈{0,1}. so that n=i=0n∑ ai2i I will assume n=k, i know that if n is even then a0 =0. so if i assume it is true for n that is Even: n+1=i=0n+1∑ ai2i...- Dank2
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- Induction Proof
- Replies: 5
- Forum: Precalculus Mathematics Homework Help
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Can I use the mean value theorem to prove that f>g for all x in (a,b)?
H'(c)= (h(b)-h(a))/b-a > 0 -
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Can I use the mean value theorem to prove that f>g for all x in (a,b)?
That there is point c where the derivative of h'(c) is parallel to the straight line connecting the two end points of the segment -
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Can I use the mean value theorem to prove that f>g for all x in (a,b)?
if f(c)<g(c) then h(c) < 0, doesn't help me much -
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Can I use the mean value theorem to prove that f>g for all x in (a,b)?
yes, they are differentiable. https://www.physicsforums.com/threads/proof-inx-x-1.900384/#post-5667094 i proved it in other way in the link above post 9. howcan i use mean value theorem to show it ? -
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Undergrad Prove ln(x) <= x-1 for positive x
that's right, so: f(x) = x-1 - Inx . f''(x) = 1 - 1/x = 0 ==> x=1. that should be either maximus or minimum f(1) = 0. now if we take the second derivative: f''(x) = 1/x^2 which means the derivative is increasing constantly and f(1) is the minimum point inthe graph, and hence x-1>=Inx