DOC PREVIEW
Pitt MATH 0220 - Exam Practice

This preview shows page 1-2 out of 5 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 5 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

MATH 0220 EXAM II NAME1. Differentiate each of the following. It’s not necessary to simplify your answers.(a) f(x) =3√1 + x + 3x2f0(x) = −3(1 + 6x)2(1 + x + 3x2)3/2(b) s(t) = arctan (2t)s0(t) =21 + 4t2(c) y =tan x1 + cos xy0(x) =(1 + cos x) sec2x + tan x sin x(1 + cos x)2(d) g(x) = ln (x + e−3x)g0(x) =1 − 3e−3xx + e−3x(e) f(x) =5(x2− 4)3f0(x) = −30x(x2− 4)4(f) y = xcos xy0(x) = xcos x−sin x ln x +cos xx2. (a) Determine the equation of the tangent line to the curve:x2sin y + 3x + 2y = 6 at the point (2, 0).2x sin x + x2cos ydydx+ 3 + 2dydx= 00 + 4dydx+ 3 + 2dydx= 0dydx= −12Therefore, the equation of t he tangent line is y = −12(x − 2)(b) Use your answer in part (a) to approximate y when x = 2.4y ≈ −0.5(2.4 − 2) = −0.5(0.4) = −0.23. Find the point(s) on the parabola y = x2that is (are) closest to the point (0, 1).Minimize Distance to (0,1) under constraint point on parabola.D =q(x − 0)2+ (y − 1)2y = x2D(y) =qy + (y − 1)2D0(y) =1 + 2(y − 1)2qy + (y − 1)22y − 1 = 0y =12x = ±s12Points are:s12,12and−s12,12.This could have been done replacing y with x2. Then:D(x) =qx2+ (x2− 1)2D0(x) =2x + 2(x2− 1)(2x)2qx2+ (x2− 1)22x + 2(x2− 1)(2x) = 04x3− 2x = 02x(2x2− 1) = 0x = 0, x = ±s12x = 0 is a local max. Therefore, the points a r es12,12and−s12,12.4. A lighthouse is 100 meters from a straight shoreline. The light turns at a rate of10 revolutions per minute (20π radians/minute), and shines a moving spot of lightalong the shore. How fast is the spo t of light moving when it’s 100 meters f r om thepoint on t he shore which is nearest the lighthouse? Be sure to include units in youranswer.Draw a straight shoreline. Now draw the different points of light on this straightshoreline and label one x. Put the light 100 meters from the shoreline. D r aw thelight from the lighthouse to some of the points, namely the one labeled x and theone that is exactly 100 meters from the lighthouse. What you have is a r ig ht trianglewith the adjacent side 100 meters and the opposite side x meters. θ is the angle ofrotation of the light. Therefore,tan θ =x100sec2θdθdt=1100dxdt2(20π)(100)m/min =dxdt5. Use Newton’s Method once to estimate the solution to the equation x = e−x. (Notethat the plot of f(x) = x − e−xis shown below.)0 1xLet x0= 0. Then f(x0) = f(0) = −1 and since f0(x) = 1+e−x, f0(x0) = f0(0) = −1and we have:x1= 0 −(−1)2=126. Determine each of the following limits. Show your work.(a) limx→0sin xex− 1L0Rule= limx→0cos xex=11= 1.(b) limx→0ex− 1cos x=01= 0.(c) limx→0(1 + 2x)1/xLet y = (1 + 2x)1/x. Then ln y =ln((1 + 2x)xandlimx→0ln y = limx→0ln (1 + 2x)xL0Rule= limx→021+2x1= 2.Now if ln y → 2, then y →


View Full Document

Pitt MATH 0220 - Exam Practice

Download Exam Practice
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Exam Practice and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Exam Practice 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?