/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 103 Calculating limits exactly Use t... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Calculating limits exactly Use the definition of the derivative to evaluate the following limits. $$\lim _{h \rightarrow 0} \frac{(3+h)^{3+h}-27}{h}$$

Short Answer

Expert verified
Answer: The exact limit of the expression as h approaches 0 is 81.

Step by step solution

01

Use the binomial theorem

We will use the binomial theorem to expand the expression \((3+h)^{3+h}\) in order to simplify the limit. The binomial theorem states: $$(x+y)^n = \sum_{k=0}^{n} \binom{n}{k} x^{n-k} y^k$$ Plugging in our values, we get: $$(3+h)^{3+h} = \sum_{k=0}^{3+h} \binom{3+h}{k} 3^{3+h-k} h^k$$ Expanding the first few terms, we get: $$(3+h)^{3+h} = \binom{3+h}{0}3^{3+h}h^0 + \binom{3+h}{1}3^{2+h}h^1 + \binom{3+h}{2}3^{1+h}h^2 + \dots$$
02

Simplify the terms

We will now simplify the terms: $$(3+h)^{3+h} = 3^{3+h} + {(3+h)}3^{2+h}h + \frac{(3+h)(2+h)}{2}3^{1+h}h^2 + \dots$$ Now put this expression back into the limit: $$\lim_{h \rightarrow 0} \frac{3^{3+h} + {(3+h)}3^{2+h}h + \frac{(3+h)(2+h)}{2}3^{1+h}h^2 + \dots -27}{h}$$
03

Cancel common terms

Now we notice that there's a common term we can cancel, which is \(3^{3+h}\): $$\lim_{h \rightarrow 0} \frac{{(3+h)}3^{2+h}h + \frac{(3+h)(2+h)}{2}3^{1+h}h^2 + \dots -27}{h}$$
04

Substitute h = 0

Now we can substitute \(h=0\) into the expression, which will give us the final limit value: $$\lim_{h \rightarrow 0} \frac{{(3+h)}3^{2+h}h + \frac{(3+h)(2+h)}{2}3^{1+h}h^2 + \dots -27}{h} = \frac{3\cdot3^{2} + \frac{3\cdot2}{2}3^1\cdot0^2 + \dots -27}{0}$$ However, this will result in division by zero, which is undefined.
05

Reexamine the expression

Since we have encountered division by zero in Step 4, let us reexamine the expression: $$\lim_{h \rightarrow 0} \frac{3^{3+h} + {(3+h)}3^{2+h}h + \frac{(3+h)(2+h)}{2}3^{1+h}h^2 + \dots -27}{h}$$ Taking a closer look, we notice that when summing up the terms and subtracting 27, the \(3^{3+h}\) term actually cancels out with -27: $$\lim_{h \rightarrow 0} \frac{{(3+h)}3^{2+h}h + \frac{(3+h)(2+h)}{2}3^{1+h}h^2 + \dots}{h}$$
06

Cancel the h term

Now we can cancel the "h" term from the numerator and denominator: $$\lim_{h \rightarrow 0} ({(3+h)}3^{2+h} + \frac{(3+h)(2+h)}{2}3^{1+h}h + \dots)$$
07

Substitute h = 0 again

Finally, let's substitute h = 0 again: $$\lim_{h \rightarrow 0} ({(3+h)}3^{2+h} + \frac{(3+h)(2+h)}{2}3^{1+h}h + \dots)= (3\cdot3^{2} + \frac{3\cdot2}{2}3^1\cdot0 + \dots)$$ After evaluating and simplifying, we get: $$3\cdot27=81$$ Therefore, the exact limit is 81: $$\lim _{h \rightarrow 0} \frac{(3+h)^{3+h}-27}{h} = 81$$

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

One of the Leibniz Rules One of several Leibniz Rules in calculus deals with higher-order derivatives of products. Let \((f g)^{(n)}\) denote the \(n\) th derivative of the product \(f g,\) for \(n \geq 1\) a. Prove that \((f g)^{(2)}=f^{\prime \prime} g+2 f^{\prime} g^{\prime}+f g^{\prime \prime}\) b. Prove that, in general, $$(f g)^{(n)}=\sum_{k=0}^{n}\left(\begin{array}{l} n \\ k \end{array}\right) f^{(k)} g^{(n-k)}$$ where \(\left(\begin{array}{l}n \\ k\end{array}\right)=\frac{n !}{k !(n-k) !}\) are the binomial coefficients. c. Compare the result of (b) to the expansion of \((a+b)^{n}\)

a. Differentiate both sides of the identity \(\cos 2 t=\cos ^{2} t-\sin ^{2} t\) to prove that \(\sin 2 t=2 \sin t \cos t\). b. Verify that you obtain the same identity for sin \(2 t\) as in part (a) if you differentiate the identity \(\cos 2 t=2 \cos ^{2} t-1\). c. Differentiate both sides of the identity \(\sin 2 t=2 \sin t \cos t\) to prove that \(\cos 2 t=\cos ^{2} t-\sin ^{2} t\).

a. Determine an equation of the tangent line and normal line at the given point \(\left(x_{0}, y_{0}\right)\) on the following curves. b. Graph the tangent and normal lines on the given graph. \(\left(x^{2}+y^{2}-2 x\right)^{2}=2\left(x^{2}+y^{2}\right)\) \(\left(x_{0}, y_{0}\right)=(2,2)\) (limaçon of Pascal)

The total energy in megawatt-hr (MWh) used by a town is given by $$E(t)=400 t+\frac{2400}{\pi} \sin \frac{\pi t}{12},$$ where \(t \geq 0\) is measured in hours, with \(t=0\) corresponding to noon. a. Find the power, or rate of energy consumption, \(P(t)=E^{\prime}(t)\) in units of megawatts (MW). b. At what time of day is the rate of energy consumption a maximum? What is the power at that time of day? c. At what time of day is the rate of energy consumption a minimum? What is the power at that time of day? d. Sketch a graph of the power function reflecting the times at which energy use is a minimum or maximum.

General logarithmic and exponential derivatives Compute the following derivatives. Use logarithmic differentiation where appropriate. $$\frac{d}{d x}(2 x)^{2 x}$$.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.