All Answers 358512 Answers

IT IS NEITHER!! THE LINES CRISS-CROSS.

Here is how you plot it:ContourPlot[{y = 14 - 4 x, -x + 4 y = 14}, {x, 25/17, 59/17}, {y, 53/17, 87/17}]

You may practice graphing it here:https://www.desmos.com/calculator

what is 54 times 6 and a half?

Learn how to use the calculator here. First, enter 54, then press "X" sign followed by 6.5 and then press the = sign. That should give you your answer.

Why is sin^-1(x) equal to arcsin(x), when the power of -1 should flip the expression to give 1/sin(x) which is cosec(x)?

I think you maybe confusing a number of things here. Sin^-1(x) and Arcsin(x) and Inverse sin(x)=THE SAME THING!!! Inverse sin(x) is often written as: Sin^-1. The power sign "^" in NOT meant to raise sin(x) to -1!!!!!!. Inverse sine or Arcsine is written like that for convenience ONLY.

Both those answers look great to me :)

In this case the -1 does not mean flip (find reciprocal) 

It mean find the angle whose sin is x ..     which is also asin x

\(If \qquad sin^{-1}(x)=\theta \qquad then \qquad sin \theta =x\\ and \qquad sin^{-1}(x)=asin\;(x)\)

I think the asin notation is much better because the -1 notation is very confusing.

If you want the reciprocation you need to write

\((sin\theta)^{-1} = \frac{1}{sin(\theta)}=Cosec(\theta)\)

what is 133 1/3% of 27?

((133.33/100) + 1) X 27=63

   25[1-(1+0.025)^-20]/0.025 =389.73

This is the PV of 20 annual payments of $25 each at an annual rate of 2.5%.

4n*2n=32

8n^2=32

n^2=32/8=4 take the sqrt of both sides

n=2

Soybean meal is 16% protein; cornmeal is 8%. How many pounds of each should be mixed together in order to get 320-Ib mixture that is 11% protein?

Let x be a portion of the 16% protein, then,

320 - x, is the portion of the 8% protein but,

.16x + .08(320 - x)=320*11%

.16x +25.6 - .08x=35.20 re-arrange

.08x=9.60 divide both sides by .08

x=120 Pounds of the 16% protein, and

320 - 120=200 Pounds of the 8% protein

Let the number of videos be=x

Let the numbet of CD's be=y, then we have:

x + y=7

14.95x + 16.88y=112.37

Solve the following system:
{14.95 x+16.88 y = 112.37
x+y = 7

In the second equation, look to solve for y:
{14.95 x+16.88 y = 112.37
x+y = 7

Subtract x from both sides:
{14.95 x+16.88 y = 112.37
y = 7-x

Substitute y = 7-x into the first equation:
{16.88 (7-x)+14.95 x = 112.37
y = 7-x

16.88 (7-x)+14.95 x = 14.95 x+(118.16-16.88 x) = 118.16-1.93 x:
{118.16-1.93 x = 112.37
y = 7-x

In the first equation, look to solve for x:
{118.16-1.93 x = 112.37
y = 7-x

118.16-1.93 x = 2954/25-(193 x)/100 and 112.37 = 11237/100:
2954/25-(193 x)/100 = 11237/100

Subtract 2954/25 from both sides:
{-(193 x)/100 = -579/100
y = 7-x

Multiply both sides by -100/193:
{x = 3
y = 7-x

Substitute x = 3 into the second equation:
Answer: | 
| {x = 3
y = 4

3(14.95) * 4(16.88) = 112.37 so Christine bought 3 videos and 4 CDs.

I divided 112.37 by 7 and the answe was closer to 16.88 so I concluded more CDs were bought than videos. And I was right.

Not very mathematical, but it got the job done :)

Average rate of change =

[h(b) - h(a)] / [b - a]     where b = 11pi/6  and a = 2pi/3

[sin(11pi/ 6)  - sin (2pi/3)] / [ 11pi/ 6  - 2pi/ 3]  =

[ -1/2 - sqrt(3)/2] / [ 11pi/6 - 4pi/6]  =

[ -1 - sqrt(3)] /[ 2(7pi/6) ] =

- [ 1 + sqrt(3)] / [7pi / 3]  =

-3[1 + sqrt(3)] / [7pi] =

about -0.3727

Thanks CPhill 

21
no jk 19

Using Melody's answer as a guide, the function has a max at (-1, 3)

And since the end behavior of the function as it approaches infinity is negative.......it has to have at least one negative root, because it would have to cross the x axis once as it approaches x = -1  from the left side

The y intercept is positive......and we have a min at (1, -1)......so the function has to cross the x axis once between x = 0 and x = 1

Likewise, the end behavior of the function is positive as is approchaes positive infinity......so....it must cross the x axis somewhere between x = 1   and infinity

Thus......the function has one negative root and two positive ones........

Solve for x:
2x^2-6x-20 = 0.

0. = 0:
2x^2-6x-20 = 0

The left hand side factors into a product with three terms:
2 (x-5) (x+2) = 0

Divide both sides by 2:
(x-5) (x+2) = 0

Split into two equations:
x-5 = 0 or x+2 = 0

Add 5 to both sides:
x = 5 or x+2 = 0

Subtract 2 from both sides:
Answer: | 
| x = 5 or x = -2

Go online to this link and learn about matrices:

https://www.mathsisfun.com/algebra/matrix-multiplying.html

25 X 1.80=45, which is the answer.

This is either a 3rd or 4th quadrant angle.....

And sine = y/r  .....we need to find x

x = [ plus/minus] sqrt (5^2 -2^2) =  [plus / minus]sqrt(21)

sec = r/x  =  (plus/ minus)5/sqrt(21)

cot = x/y  = (plus/ minus) sqrt(21) / 2

413 Miles.

The answer is: D=-0.1

HI, 

13/120 = 0,1083333333 

I am sorry but you could have just tape in your calculator, nope ? 

Enjoy your day, god bless you