Difference between revisions of "009A Sample Final 3, Problem 2"

From Grad Wiki
Jump to navigation Jump to search
 
(2 intermediate revisions by the same user not shown)
Line 1: Line 1:
 
<span class="exam"> Find the derivative of the following functions:
 
<span class="exam"> Find the derivative of the following functions:
  
<span class="exam">(a) &nbsp;<math>g(\theta)=\frac{\pi^2}{(\sec\theta -\sin 2\theta)^2}</math>
+
<span class="exam">(a) &nbsp;<math style="vertical-align: -18px">g(\theta)=\frac{\pi^2}{(\sec\theta -\sin 2\theta)^2}</math>
  
<span class="exam">(b) &nbsp;<math>y=\cos(3\pi)+\tan^{-1}(\sqrt{x})</math>
+
<span class="exam">(b) &nbsp;<math style="vertical-align: -5px">y=\cos(3\pi)+\tan^{-1}(\sqrt{x})</math>
  
{| class="mw-collapsible mw-collapsed" style = "text-align:left;"
+
<hr>
!Foundations: &nbsp;
+
[[009A Sample Final 3, Problem 2 Solution|'''<u>Solution</u>''']]
|-
 
|'''1.''' '''Chain Rule'''
 
|-
 
|&nbsp; &nbsp; &nbsp; &nbsp; <math>\frac{d}{dx}(f(g(x)))=f'(g(x))g'(x)</math>
 
|-
 
|'''2.''' '''Trig Derivatives'''
 
|-
 
|&nbsp; &nbsp; &nbsp; &nbsp; <math>\frac{d}{dx}(\sin x)=\cos x,\quad\frac{d}{dx}(\sec x)=\sec x \tan x</math>
 
|-
 
|'''3.''' '''Inverse Trig Derivatives
 
|-
 
|&nbsp; &nbsp; &nbsp; &nbsp; <math>\frac{d}{dx}(\tan^{-1} x)=\frac{1}{1+x^2}</math>
 
|
 
|}
 
  
  
'''Solution:'''
+
[[009A Sample Final 3, Problem 2 Detailed Solution|'''<u>Detailed Solution</u>''']]
  
'''(a)'''
 
  
{| class="mw-collapsible mw-collapsed" style = "text-align:left;"
 
!Step 1: &nbsp;
 
|-
 
|First, we write
 
|-
 
|&nbsp; &nbsp; &nbsp; &nbsp;<math>g(\theta)=\pi^2(\sec\theta -\sin 2\theta)^{-2}.</math>
 
|-
 
|Now, using the Chain Rule, we have
 
|-
 
|&nbsp; &nbsp; &nbsp; &nbsp;<math>g'(\theta)=(-2)\pi^2(\sec\theta -\sin 2\theta)^{-3}(\sec\theta -\sin 2\theta)'.</math>
 
|}
 
 
{| class="mw-collapsible mw-collapsed" style = "text-align:left;"
 
!Step 2: &nbsp;
 
|-
 
|Now, using the Chain Rule a second time, we get
 
|-
 
|&nbsp; &nbsp; &nbsp; &nbsp; <math>\begin{array}{rcl}
 
\displaystyle{g'(\theta)} & = & \displaystyle{(-2)\pi^2(\sec\theta -\sin 2\theta)^{-3}(\sec\theta -\sin 2\theta)'}\\
 
&&\\
 
& = & \displaystyle{(-2)\pi^2(\sec\theta -\sin 2\theta)^{-3}(\sec\theta\tan\theta -\cos (2\theta)(2\theta)')}\\
 
&&\\
 
& = & \displaystyle{(-2)\pi^2(\sec\theta -\sin 2\theta)^{-3}(\sec\theta\tan\theta -\cos (2\theta)(2))}\\
 
&&\\
 
& = & \displaystyle{\frac{-2\pi^2(\sec\theta\tan\theta -2\cos (2\theta))}{(\sec\theta -\sin 2\theta)^{3}}.}
 
\end{array}</math>
 
|}
 
 
'''(b)'''
 
 
{| class="mw-collapsible mw-collapsed" style = "text-align:left;"
 
!Step 1: &nbsp;
 
|-
 
|
 
|-
 
|
 
|}
 
 
{| class="mw-collapsible mw-collapsed" style = "text-align:left;"
 
!Step 2: &nbsp;
 
|-
 
|
 
|}
 
 
 
{| class="mw-collapsible mw-collapsed" style = "text-align:left;"
 
!Final Answer: &nbsp;
 
|-
 
|&nbsp; &nbsp;'''(a)'''&nbsp; &nbsp; <math>g'(\theta)=\frac{-2\pi^2(\sec\theta\tan\theta -2\cos (2\theta))}{(\sec\theta -\sin 2\theta)^{3}}</math>
 
|-
 
|&nbsp; &nbsp;'''(b)'''&nbsp; &nbsp;
 
|}
 
 
[[009A_Sample_Final_3|'''<u>Return to Sample Exam</u>''']]
 
[[009A_Sample_Final_3|'''<u>Return to Sample Exam</u>''']]

Latest revision as of 16:34, 2 December 2017

Find the derivative of the following functions:

(a)  

(b)  


Solution


Detailed Solution


Return to Sample Exam