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The R online test assesses candidates' knowledge of programming in the R language and their ability to leverage commonly used built-in functions.

It's an ideal test for pre-employment screening. A good R developer needs to be able not only to solve problems using R as the programming language but also recognize when to take advantage of its rich set of built-in functions.

This test requires candidates to be able to solve coding problems in the R language.

Implement the function *findRoots* to find the roots of the quadratic equation: ax^{2} + bx + c = 0. The function should return a vector containing roots in any order. If the equation has only one solution, the function should return that solution as both elements of the vector. The equation will always have at least one solution.

The roots of the quadratic equation can be found with the following formula:

For example, *findRoots(2, 10, 8)* should return a vector containing *(-1, -4)* or *(-4, -1)* as the roots of the equation 2x^{2} + 10x + 8 = 0 are -1 and -4.

A company stores login data and passwords in two different containers:

- A
*DataFrame*with the columns:*id*,*name*, and*verified*. - A matrix where each row contains, in order:
*id*and*password*.

The first column of any row in the matrix corresponds to the *id *column in the *DataFrame*. Elements on the same row/index in both the *DataFrame *and the *matrix *have the same *id*.

Implement the function *loginTable* that accepts these two containers and returns a new *DataFrame *that contains the following columns:

- The
*id*column from the*idNameVerified DataFrame*. - The
*name*column from the*idNameVerified DataFrame*. - A new column, called
*password*that contains the password from the*idPassword*matrix.

For example, the following code snippet:

```
idNameVerified = data.frame(id = c(1, 2),
name = c("JohnDoe", "AnnFranklin"),
verified = c(TRUE, FALSE))
idPassword = matrix(c(1, 2, 987340123, 187031122),
nrow=2,
ncol=2)
print(loginTable(idNameVerified,idPassword))
```

Should print:

id name password 1 1 JohnDoe 987340123 2 2 AnnFranklin 187031122

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