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2 years ago

What is a variable in mathematics?

Mathematics

2 answers:

Dmitrij [34]2 years ago

7 0

Answer:

variable, In algebra, a symbol (usually a letter) standing in for an unknown numerical value in an equation. Commonly used variables include x and y (real-number unknowns), z (complex-number unknowns), t (time), r (radius), and s (arc length).

Lubov Fominskaja [6]2 years ago

7 0

Answer:

Step-by-step explanation:

In Maths, a variable is an alphabet or term that represents an unknown number or unknown value or unknown quantity. The variables are specially used in the case of algebraic expression or algebra. For example, x+9=4 is a linear equation where x is a variable, where 9 and 4 are constants.

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Find the solutions for a triangle with a = 16, c =12, and B = 63º.

maks197457 [2]

Answer:

b. A = 71.6°; C = 45.40°; b =15.0

Step-by-step explanation:

The missing values can be found with the help of the Law of Cosine and properties of triangles:

Side b (Law of Cosine)

$b = \sqrt{a^{2}+c^{2}-2\cdot a \cdot c \cdot \cos B}$

$b = \sqrt{16^{2}+12^{2}-2\cdot (16)\cdot (12) \cdot \cos 63^{\circ}}$

$b \approx 15.022$

Angle A (Law of Cosine)

$\cos A = -\frac{a^{2} - b^{2}-c^{2}}{2\cdot b \cdot c}$

$\cos A = - \frac{16^{2}-15.022^{2}-12^{2}}{2\cdot (15.022)\cdot (12)}$

$\cos A = 0.315$

$A= \cos^{-1} 0.315$

$A \approx 71.639^{\circ}$

Angle C (Sum of internal angles in triangles)

$C = 180^{\circ} - 63^{\circ} - 71.639^{\circ}$

$C = 45.361^{\circ}$

Hence, the right answer is B.

6 0

3 years ago

Find the directional derivative of f(x,y,z)=z3−x2yf(x,y,z)=z3−x2y at the point (−5,5,2)(−5,5,2) in the direction of the vector v

olga_2 [115]

We are given

$f=z^3 -x^2y$

Firstly, we can find gradient

so, we will find partial derivatives

$f_x=0 -2xy$

$f_x=-2xy$

$f_y=0 -x^2$

$f_y=-x^2$

$f_z=3z^2$

now, we can plug point (-5,5,2)

$f_x=-2*-5*5=50$

$f_y=-(-5)^2=-25$

$f_z=3(2)^2=12$

so, gradient will be

$gradf=(50,-25,12)$

now, we are given that

it is in direction of v=⟨−3,2,−4⟩

so, we will find it's unit vector

$|v|=\sqrt{(-3)^2+(2)^2+(-4)^2}$

$|v|=\sqrt{29}$

now, we can find unit vector

$v'=(\frac{-3}{\sqrt{29} } , \frac{2}{\sqrt{29} } , \frac{-4}{\sqrt{29} })$

now, we can find dot product to find direction of the vector

$dir=(gradf) \cdot (v')$

now, we can plug values

$dir=(50,-25,12) \cdot (\frac{-3}{\sqrt{29} } , \frac{2}{\sqrt{29} } , \frac{-4}{\sqrt{29} })$

$dir=(-\frac{150}{\sqrt{29} } - \frac{50}{\sqrt{29} } - \frac{48}{\sqrt{29} })$

$dir=-\frac{248\sqrt{29}}{29}$ .............Answer

7 0

3 years ago

Read 2 more answers

What is the curve : y= -2x

arsen [322]

The curve is a linear equation.

<h3>What type of curve is the given equation?</h3>

It is actually a linear equation, meaning that this is a straight line, not a an actual "curve".

To view the "shape" of the curve, you need to graph it.

You could use a program or do it by hand, to do it by hand, you need to evaluate a lot of points of the equation, and then graph them to see the general behavior of the equation.

In this case, I graphed it with a program, and in the image, you can see that this is a linear equation that decreases as the variable increases.

If you want to learn more about linear equations, you can read:

brainly.com/question/4074386