Simplify the following expression by expanding the and collecting like terms -2 (-8x minus 4) + 3

Find the dot product of the position vectors whose terminal points are (14, 9) and (3, 6).

erma4kov [3.2K]

Answer:

Step-by-step explanation:

The formula for the dot product of vectors is

u·v = |u||v|cosθ

where |u| and |v| are the magnitudes (lengths) of the vectors. The formula for that is the same as Pythagorean's Theorem.

$|u|=\sqrt{14^2+9^2}$ which is $\sqrt{277}$

$|v|=\sqrt{3^2+6^2}$ which is $\sqrt{45}$

I am assuming by looking at the above that you can determine where the numbers under the square root signs came from. It's pretty apparent.

We also need the angle, which of course has its own formula.

$cos\theta=\frac{uv}{|u||v|}$ where uv has ITS own formula:

uv = (14 * 3) + (9 * 6) which is taking the numbers in the i positions in the first set of parenthesis and adding their product to the product of the numbers in the j positions.

uv = 96.

To get the denominator, multiply the lengths of the vectors together. Then take the inverse cosine of the whole mess:

$cos^{-1}\theta=\frac{96}{111.64676}$ which returns an angle measure of 30.7. Plugging that all into the dot product formula:

$u*v=\sqrt{277}*\sqrt{45}cos(30.7)$ gives you a dot product of 96

6 0

2 years ago

Claire makes bracelets using blue and red beads

Kazeer [188]

What is the question?

5 0

2 years ago

Read 2 more answers

g If a snowball melts so that its surface area decreases at a rate of 4 cm2/min, find the rate (in cm/min) at which the diameter

maks197457 [2]

Answer:

Rate of change of the diameter is equal to 0.053cm/min

Step-by-step explanation:

A snowball is of the shape of a sphere

Surface area of Sphere (S)= $4*pi*R^2$

Rate of change of surface area

dS/dt = -4 $cm^2/min$

the negative sign indicates the surface area is decreasing.

Radius = d/2 where d represents diameter

using this is the surface area equation

S = $4*pi*(d/2)^2$

= $pi*d^2$

dS/dt = 2*pi*d*d(d)/dt

4 = 2*pi*d*(d)/dt

d(d)/dt = 2/12*pi= $\frac{1}{6pi}$ cm/min

so the rate of change of the diameter is equal to 0.053cm/min

5 0

1 year ago

PLEASE HELP FAST 100 EASY POINTS WILL MARK BRAINLEST!!!

spin [16.1K]

Answer:

$y=-1x+8 \\or\\y=-x+8$

Step-by-step explanation:

Okay so we know that line on the triangle DEF that's parallel to the line BC is EF. This because they have the same slope and we can prove that while solving for slope-intercept form.

First we figure out our points for both the lines:

BC: $B=(-2,4) \\C=(1,1)$

EF: $E=(4,4)\\F=(6,2)$

Now that we have our points we can use the slope formula to prove these two line have the same slope and are therefore parallel to eachother:

$\frac{y_1-y_2}{x_1-x_2}$ = Slope Formula

BC = $\frac{4-1}{-2-1} =\frac{3}{-3} =\frac{-3}{3} =-1$

EF = $\frac{4-2}{4-6} =\frac{2}{-2}=\frac{-2}{2}= -1$

So now we proved that both of these lines have a slope of -1. Then we can use the slope intercept formula and one of the points from the line EF to find the y-intercept of the of line EF:

Let's use point = $(4,4)$

$y=4,m=-1,x=4,b=?$

$y=mx+b\\4=-1(4)+b\\4=-4+b\\(+4) 4=-4+b(+4)\\8=b$

We used the formula and found that the y-intercept was $(0,8)$ , so now we plug in all of our answers:

$y=-1x+8$

This is the complete answer but if you wanted to simplify it more you could write it as $y=-x+8$ , cause as long as you make the x negative in the equation it will always be as if you multiplied it by -1.

7 0

1 year ago

Identify the angle pair?

natta225 [31]

Answer:

Alternate Exterior Angles

6 0

2 years ago