I know that elements in page objects can be initialized and used in both the following ways     Option 1:   public class LoginPage  {    WebDriver driver;    By usernameLocator = By.id("username");    By passwordLocator = By.id("password");    By loginButton = By.className("radius");   public LoginPage(WebDriver driver)  {     this.driver=driver;  }  public void with(String username,String password)  {     driver.findElement(usernameLocator).sendKeys(username);     driver.findElement(passwordLocator).sendKeys(password);     driver.findElement(loginButton).click();  } }   and also using PageFactory concept     Option 2:   public class LoginPage  {   WebDriver driver;   @FindBy(how=How.ID, using="username")  public WebElement usernameLocator;   @FindBy(how=How.ID, using="password")  public WebElement passwordLocator;   @FindBy(how=How.CLASS_NAME, using="radius")  public WebElement loginButton;   public LoginPage(WebDriver driver)  {      this.driver=driver;          //Initialize elements     PageFactory.initElements(driver, this);  }   public void with(String username, String password)  {     usernameLocator.sendKeys(username);     passwordLocator.sendKeys(password);     loginButton.click();  } }      In the above two options:    Which among the both options is a better choice? What are the trade-off's between both the following options?   Please explain
I am a beginner in learning selenium Webdriver. I am not able to understand how page object and factory models works and how it can be beneficial?    Kindly help me explain it with detailed explanation.
Can ovulation and menstruation occur simultaneously? Is that possible that ovulation happens in the time of actual menstrual haemorrhage in human females - let say in a case that woman has 21 day cycle and her menstrual period is 7 days?   If yes, does it means that in this particular case the woman has lower chances to conceive? How do I create a file of size 10M, format it with ext3 filesystem and then mount it in /media/fuse?  I tried with  mkfs -t ext3 file   then to mount it  mount -t ext3 file /media/fuse   It didn't work because it said that file wasn't a block device. Can anybody help me? How to configure Jaybird with hibernate How do I get a consistent byte representation of strings in C# without manually specifying an encoding? Alignment of numbers on the individual bars Proving that $\lim\limits_{x\to\infty}f'(x) = 0$ when $\lim\limits_{x\to\infty}f(x)$ and $\lim\limits_{x\to\infty}f'(x)$ exist What are the visa (or any other crucial) requirements of Bhutan for tourists? I heard that access to Bhutan is quite restricted for all people of outside South-Asian countries?  Can I have the details on that? Changing projection of shapefile in QGIS How do I change the projection of my shapefile using QGIS? The default projection is set to EPSG:3003, I want to change it to WGS84 EPSG:32632. When I do a reprojection or I change projection in the properties mask I don't have the correct result. On the left, I have the plan coordinates but they are not correct for the EPSG shown on the right: I'm trying to delete some old flow which are inactive via workbench. DestructiveChanges.xml &lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt; &lt;Package xmlns=&quot;http://soap.sforce.com/2006/04/metadata&quot;&gt;     &lt;types&gt;         &lt;members&gt;Advanced_Round_Robin&lt;/members&gt;         &lt;name&gt;Flow&lt;/name&gt;     &lt;/types&gt;Ï &lt;/Package&gt;  package.xml &lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt; &lt;Package xmlns=&quot;http://soap.sforce.com/2006/04/metadata&quot;&gt;       &lt;version&gt;48.0&lt;/version&gt; &lt;/Package&gt;  I've added both file in zip and in workbench when I deploy using this zip file I get below error.  insufficient access rights on cross-reference id   What permission I need to have to perform this action? Also is there way I can delete few version of same flow only? Like keep only last 3-4 version and delete all previous version of given flow? Thank you. I'm seeking for a proof of the following:     Let $A$ be an invertible matrix. Then the determinant of $A^{-1}$ equals:   $$\left|A^{-1}\right|=|A|^{-1} $$   I don't know where to begin the proof. Any suggestions? I'm looking to simultaneously send the same email to multiple recipients.  Let's say I want to email John and Bill the same email, I want them to be in the "To:" field, but I don't want them to see each other in the address list.  I don't want to bcc them both because then they see they are bcc'd.  I want them to each get their own copy of the identical email and to have 2 emails in my sent folder - one for each of them.  Essentially I want the same result as if I separately sent them each the identical email, but I'd like to do it in fewer steps.  Can I accomplish this either natively or with a plug-in, or some pre-existing code?  NOTE: I am looking to do this interactively (in real time), not in batch. order of a sylow p-subgroup If $a \cdot a = 1$ then $a = 1$ or $a = -1$ Let $F$ be a field.   And let $a \in F$ such that $a \cdot a = 1$.  Claim: $a = 1$ or $ a = -1$  Before, I begin with the proof I cannot understand what $ a = -1$ represents...  Is $a = -1$ representing the inverse of $a$?   I am capable of getting to $a = 1$ with no trouble, but how do you get the $-$ sign to show up in your proof?   Proof: This is my attempt at getting to $a=-1$.  If $a = 0$ then we have $0 \cdot 0 = 0 \neq 1$. Then this implies that $a \neq 0$ which implies that $ \exists b \in F,$ s.t. $a \cdot b = 1$, i.e. $b$ is the multiplicative inverse of $a$.  Knowing this fact prove as follows...:  $a \cdot a = 1 \implies$ $ (a \cdot a) \cdot b = 1 \cdot b \implies$ $a \cdot (a \cdot b) = 1 \cdot b \implies$ $a \cdot 1 = 1 \cdot b \implies$ $ 1 \cdot a =1 \cdot b \implies$ $a = b$.   But since $b$ is the multiplicative inverse of $a$ is this enough to say that $a = -1$? Logic soundness and completeness I have to do a number of similar type questions, but I am having trouble grasping the general concepts around soundness and completeness. I have read up on the general definitions and think I understand them, but when asked to show something like the following I come up blank. Thanks for any ideas/help.   Show that the following propositional proof system, PCa, is sound but not complete.  PCa  Connectives (and constants) ∨, ∧, →, ↔, ¬, 0, 1  Axioms All tautologies of the form F→F  Rules of inference Hypothetical Syllogism Torque direction meaning I apologize if this question is dumb, but I've looked all over for a straightforward answer, and either I can't find one or either the terms are too complex for me to understand. I have only a rudimentary knowledge of Mechanics, but I do understand basic Linear Algebra. So torque, mathematically, is the cross product of the radial distance vector and a force vector. This cross-product gives another vector that is orthogonal to both vectors and it points either outside or towards the &quot;page&quot; (in the context of a two-dimensional diagram). Assuming this is correct, I do not understand what it pointing in or out means. Does it even have a physical, intuitive meaning? The best answer I've been able to come up with is that it's just a mathematical convention with no actual physical meaning, meant to provide a framework within which operations between torque vectors, such as addition and subtraction, make sense. Am I correct or way off the mark here? My try, using $x = \sec(u)$ substitution:  $$ \begin{eqnarray} \int \frac{\sqrt{x^2-1}}{x} \mathrm{d}x &amp;=&amp; \int \frac{\sqrt{\sec^2(u) - 1}}{\sec(u)}\tan(u)\sec(u) \mathrm{d}u \\ &amp;=&amp; \int \tan^2(u) \mathrm{d}u \\ &amp;=&amp; \tan(u) - u + C \\ &amp;=&amp; \tan(arcsec(x)) - arcsec(x) + C \end{eqnarray} $$  However, according to , the answer should be: $$ \int \frac{\sqrt{x^2-1}}{x} \mathrm{d}x = \sqrt{x^2-1}+\arctan \left( \frac{1}{\sqrt{x^2-1}} \right)+C $$ When I derive this last answer I don't get back the integrand, but rather: $$ \frac{\mathrm d}{\mathrm d x}\left(\sqrt{x^2-1}+\arctan \left( \frac{1}{\sqrt{x^2-1}} \right)+C\right) = \frac{x}{\sqrt{x^2-1}}- \frac{x}{(x^2-1)^{3/2}\left(1+\frac{1}{x^2-1}\right)} $$  I don't know how to simplify this expression more. Also, I am unable to check whether my answer is correct because I don't know how to find the derivative of $arcsec(x)$.  Can someone check my calculations and tell me where I've done something wrong and how one can simplify the last expression to get back the integrand? Can I use images rendered with blender for commercial use? If I make a scene and then render it with BR or Cycles, am I allowed to use that image in a commercial project? Do I need to include any copyright notice or license? How to run a program without typing the full path? System utilities such as ls don't need to have the full path typed before executing them. However, to execute Netbeans, I have to type /home/chris/netbeans-7.0.1/bin/netbeans. How can I make it so that I only have to type netbeans? Adding two numbers concatenates them instead of calculating the sum Assume that $X$ and $Y$ are independent random variables with $X \sim \exp(\lambda)$ and $Y \sim \exp(\mu)$. It is impossible to obtain direct observations of $X$ and $Y$. Instead, we observe the random variables $Z$ and $W$, where $Z = \min\{X,Y\}$ and $W =1$ if $Z=X$ and $W=0$ if $Z=Y$.  How to find the joint distribution of $Z$ and $W$?