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3 years ago

Estimate, then find the sum of 312+397

Mathematics

2 answers:

Irina18 [472]3 years ago

6 0

312 397 ___ 709 that the answer if summary number by number you going to find it.

Klio2033 [76]3 years ago

4 0

The estimate is 700 and the answer is 709.I did this all on paper so don't worry I am very good at estimating and adding.

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-92 + -68 ? pls hurry !

Bezzdna [24]

Answer:

its -160

Step-by-step explanation:

7 0

3 years ago

Jim nasium is building a tree house for histwo daughters. He cuts 12 pieces of wood from a board that is 128 inches long.He cuts

AnnyKZ [126]

Answer:

6.75 inches each

Step-by-step explanation:

128 less 2 inches for the cuttingblade

5 x 15.75 = 78.75

126 - 78.75 =47.25

47.25/7 = 6.75

5 0

3 years ago

20x+6=y<br><br> 19x+7=y<br><br> answer please

morpeh [17]

Step-by-step explanation:

what we trying to find the value of x and y

20x+6=y

x intercept,y=0

20x+6=0-6

20x/20=-6/20

×=-0.3

y intercept,x=0

20(0)+6=y

0+6=y

6=y

(-0.3,0)

19x+7=y

y intercept,x =0

19(0)+7=y

0+7=y

7=y

x intercept,y=0

19x+7=0-7

19x=-7

19x/19=-7/19

x=-0.37

4 0

2 years ago

Help Me! ASAP! What is the slope of the line?

Natalka [10]

Answer:

slope is 2

Step-by-step explanation:

Hope this helps. Pls give brainliest.

6 0

3 years ago

Read 2 more answers

The equation r(t) = sin(4t)i + cos(4t)j, 0t≥0 describes the motion of a particle moving along the unit circle. Answer the follo

lorasvet [3.4K]

Answer:

a) Particle has a constant speed of 4, b) Velocity and acceleration vector are orthogonal to each other, c) Clockwise, d) False, the particle begin at the point (0,1).

Step-by-step explanation:

a) Let is find first the velocity vector by differentiation:

$\vec v = \frac{dr_{x}}{dt} i + \frac {dr_{y}}{dt} j$

$\vec v = 4\cdot \cos 4t\, i - 4 \cdot \sin 4t \,j$

$\vec v = 4 \cdot (\cos 4t \, i - \sin 4t\,j)$

Where the resultant vector is the product of a unit vector and magnitude of the velocity vector (speed). Velocity vector has a constant speed only if magnitude of unit vector is constant in time. That is:

$\|\vec u \| = 1$

Then,

$\| \vec u \| = \sqrt{\cos^{2} 4t + \sin^{2}4t }$

$\| \vec u \| = \sqrt{1}$

$\|\vec u \| = 1$

Hence, the particle has a constant speed of 4.

b) The acceleration vector is obtained by deriving the velocity vector.

$\vec a = \frac{dv_{x}}{dt} i + \frac {dv_{y}}{dt} j$

$\vec a = 16\cdot (-\sin 4t \,i -\cos 4t \,j)$

Velocity and acceleration are orthogonal to each other only if $\vec v \bullet \vec a = 0$ . Then,

$\vec v \bullet \vec a = 64 \cdot (\cos 4t)\cdot (-\sin 4t) + 64 \cdot (-\sin 4t) \cdot (-\cos 4t)$

$\vec v \bullet \vec a = -64\cdot \sin 4t\cdot \cos 4t + 64 \cdot \sin 4t \cdot \cos 4t$

$\vec v \bullet \vec a = 0$

Which demonstrates the orthogonality between velocity and acceleration vectors.

c) The particle is rotating clockwise as right-hand rule is applied to model vectors in 2 and 3 dimensions, which are associated with positive angles for position vector. That is: $t \geq 0$

And cosine decrease and sine increase inasmuch as t becomes bigger.

d) Let evaluate the vector in $t = 0$ .

$r(0) = \sin (4\cdot 0) \,i + \cos (4\cdot 0)\,j$

$r(0) = 0\,i + 1 \,j$

False, the particle begin at the point (0,1).

7 0

3 years ago