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3 years ago

Solve the given equation by completing the square.

Mathematics

2 answers:

Dmitriy789 [7]3 years ago

6 0

Answer:

a = -4, b = 3 and c = 6 (OR)

a = -4, b = -3 and c = 6

Step-by-step explanation:

$x^{2} +8x = 38$

Add 16 to both sides.

$x^{2} +8x+16 = 38 + 16$

$(x+4)^{2} =54$

$x + 4 = \sqrt{54}$ or $x + 4 = -\sqrt{54}$

$x+4=3\sqrt{6}$ or $x+4=-3\sqrt{6}$

$x=-4+3\sqrt{6}$ or $x=-4-3\sqrt{6}$

Therefore, a = -4, b = 3 and c = 6 (OR)

a = -4, b = -3 and c = 6

alexgriva [62]3 years ago

5 0

Answer

i got it right a = -4, b = 3 and c = 6 (OR)

a = -4, b = -3 and c = 6

Step-by-step explanation:

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What will make this equation true? -3 y=18

Virty [35]

Answer:

nothing

Step-by-step explanation:

you cant make this equation true!!

8 0

3 years ago

Marine biologists have determined that when a shark detectsthe presence of blood in the water, it will swim in the directionin w

siniylev [52]

Solution :

a). The level curves of the function :

$C(x,y) = e^{-(x^2+2y^2)/10^4}$

are actually the curves

$e^{-(x^2+2y^2)/10^4}=k$

where k is a positive constant.

The equation is equivalent to

$x^2+2y^2=K$

$\Rightarrow \frac{x^2}{(\sqrt K)^2}+\frac{y^2}{(\sqrt {K/2})^2}=1, \text{ where}\ K = -10^4 \ln k$

which is a family of ellipses.

We sketch the level curves for K =1,2,3 and 4.

If the shark always swim in the direction of maximum increase of blood concentration, its direction at any point would coincide with the gradient vector.

Then we know the shark's path is perpendicular to the level curves it intersects.

b). We have :

$\triangledown C= \frac{\partial C}{\partial x}i+\frac{\partial C}{\partial y}j$

$\Rightarrow \triangledown C =-\frac{2}{10^4}e^{-(x^2+2y^2)/10^4}(xi+2yj),$ and

$\triangledown C$ points in the direction of most rapid increase in concentration, which means $\triangledown C$ is tangent to the most rapid increase curve.