A student solved a quadratic equation as shown here:

Mathematics

1 answer:

djverab [1.8K]3 years ago

6 0

Answer:

x = 3/2 or x = -4

Step-by-step explanation:

The identifiable error the students have is that before the left hand side of the equation is factorized, the right hand side value of 12 ought to be brought to the left hand side, leaving a net value of zero on the right hand side. Then whatever is factored on the left hand side is then equated to zero and then we can find the two values of x after setting each of the individual factors to zero

We proceed as follows;

$2x^{2} + 5x = 12\\2x^{2} + 5x - 12 = 0\\2x^{2} + 8x -3x -12 = 0\\2x(x+4) -3(x+4) = 0\\(2x-3)(x+4) = 0\\2x-3 = 0 or x+4 =0\\2x=3 or x=-4\\x = 3/2 or x= -4\\x = 1.5 or- 4$

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1. Evaluate the function f(x)=3x-1 using the domain of -2, 0, 3, and 5. Results are to be shown in a table.

IceJOKER [234]

Answer:

See explanation

Step-by-step explanation:

You are given the function $f(x)=3x-1$

The domain of the function are all possible values of variable x, so you can find f(x) for x=-2, 0, 3, 5:

$f(-2)=3\cdot (-2)-1=-6-1=-7\\ \\f(0)=3\cdot 0-1=0-1=-1\\ \\f(3)=3\cdot 3-1=9-1=8\\ \\f(5)=3\cdot 5-1=15-1=14$

The table is

$\begin{array}{cc}x&f(x)\\-2&-7\\0&-1\\3&8\\5&14\end{array}$

The inverse function $f^{-1}(x)$ has the domain which is the range of the function f(x) (all possible values of f(x)), so the domain of inverse function is {-7,-1,8,14}