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3 years ago

Solve x2 + 4x − 4 = 0

Mathematics

2 answers:

hoa [83]3 years ago

7 0

Answer:

third option

Step-by-step explanation:

Given

x² + 4x - 4 = 0 ( add 4 to both sides )

x² + 4x = 4

Using the method of completing the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(2)x + 4 = 4 + 4, that is

(x + 2)² = 8 ( take the square root of both sides )

x + 2 = ± $\sqrt{8}$ = ± 2 $\sqrt{2}$ ( subtract 2 from both sides )

x = - 2 ± 2 $\sqrt{2}$

Mumz [18]3 years ago

5 0

The answer is the third choice

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An object dropped from a height of 600 feet has a height, h(t), in feet after t seconds have elapsed, such that h(t)=600 - 16t^2

gulaghasi [49]

Answer:

t as a function of height h is t = √600 - h/16

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Step-by-step explanation:

Function for height is h(t) = 600 - 16t²

where t = time lapsed in seconds after an object is dropped from height of 600 feet

t as a function of height h

replacing the function with variable h

h = 600 - 16t²

Solving for t

Subtracting 600 from both side

h - 600 = -16t²

Divide through by -16

600 - h/ 16 = t²

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√600 - h/16 = t

Therefore, t = √600 - h/16

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t = √600 - h/16

substituting h = 50 in the equation

t = √600 - 50/16

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4 years ago

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3 years ago

2.<br> Which of the functions below is an inverse of the quadratic function f(x) = x2 - 3 ?

mezya [45]

Answer:

the inverse of the quadratic function $f(x) = x^2 - 3$ is $\mathbf{f^{-1}(x)=\pm \sqrt{x+3}}$

Step-by-step explanation:

We need to find inverse of the quadratic function $f(x) = x^2 - 3$

Let

$y=x^2-3$

Replace x and y

$x=y^2-3$

Now, we will solve for y

Adding 3 on both sides

$x+3=y^2-3+3$

$x+3=y^2$

Taking square root on both sides

$\sqrt{y^2}=\sqrt{x+3}\\y=\pm \sqrt{x+3}$

Now replace y with $f^{-1}(x)$

$f^{-1}(x)=\pm \sqrt{x+3}$

So, the inverse of the quadratic function $f(x) = x^2 - 3$ is $\mathbf{f^{-1}(x)=\pm \sqrt{x+3}}$

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3 years ago