Find the exact value of cos2theta if sin2theta=3/4 and theta is between 0 and 90 degree

Answer:

:)

Step-by-step explanation:

[tex]M = 3x^2y^3-4xy +x^3y\\\\2M = 2 \times (3x^2y^3-4xy +x^3y) \\\\[/tex]

      [tex]= 6x^2y^3 - 8xy + 2x^3y[/tex]

[tex]N = -2x^3y + 6x^2y^3 -8xy -8[/tex]

   [tex]= 6x^2y^3 -8xy -2x^3y -8[/tex]                 [tex][ re-arranging \ the \ terms][/tex]

a)

[tex]2 M - N = ( 6x^2y^3 -8xy +2x^3y) - (6x^2y^3-8xy -2x^3y - 8)[/tex]

            [tex]= 6x^2y^3 - 8xy +2x^3y -6x^2y^3 +8xy +2x^3y + 8\\\\= 4x^3y +8[/tex]

b)

[tex]2M - N \ for \ x = -1 \ and \ y = 2: (4(-1)^3\times (2)) + 8 = -8 + 8 = 0[/tex]

Answer:

Step-by-step explanation:

not sure if i am right but go off process of elimination

A is a not it to get slope you need to do Y=Mx+b because the slope should be 1.3 and if you get the deciml form of 3 over 9 it would be 0.75

and if you do same process on all of then you will see it is B

Given:

Radius of a circle = 21 m

Area of a sector of the circle = 27.72 m²

To find:

The angle at the center of the circle.​

Solution:

The area of a second is:

[tex]A=\pi r^2\times \dfrac{\theta}{360^\circ}[/tex]

Where, r is the radius of the circle and [tex]\theta[/tex] is the central angle.

Putting [tex]\pi=\dfrac{22}{7},\ r=21,\ A=27.72[/tex] in the above formula, we get

[tex]27.72=\dfrac{22}{7}\times (21)^2\times \dfrac{\theta}{360^\circ}[/tex]

[tex]27.72=1386\times \dfrac{\theta}{360^\circ}[/tex]

[tex]27.72=3.85^\circ \times \theta[/tex]

[tex]\dfrac{27.72}{3.85^\circ }=\theta[/tex]

[tex]7.2^\circ=\theta[/tex]

Therefore, the central angle of the sector is [tex]7.2^\circ[/tex].

Answer:

It would be 1 or just w

Step-by-step explanation:

Answer:

$5.50

Step-by-step explanation:

10 - 4.50 = 5.50

Answer:

250×

Step-by-step explanation:

The ocular lens of the compound microscope is 10×

The objective lens of the compound microscope is 25×

Therefore the total magnification can be calculated as follows

= 10×25

= 250

Hence the total magnification of the compound microscope is 250×

Answer:

96

Step-by-step explanation:

120/1.25=96

Noah needs to sell 96 slices of pizza to earn $120.

Answer:

x = 72.09555249

Step-by-step explanation:

Since this is a right angle, we can use trig functions

tan x = opp / adj

tan x = 65/21

Taking the inverse tan of each side

tan ^-1 ( tan x) = tan ^-1 ( 65/21)

x = 72.09555249

Answer:

we have,AD=x cmBC=AD=x cmAB=2AD=2x cmDC=4 cm+AB=(4+2x)cmPerimeter of the trapezium, p=38 cm

Answer:

160 for each

Step-by-step explanation:

A normal distribution means that mean = median = mode. Furthermore, in a normal distribution, 68% of values are within 1 standard deviation of the mean, 95% of values are within 2 standard deviations, and 99.7% are within 3 standard deviation.

The mean is 150 and the standard deviation is 15. 165 and 135 1 standard deviation away from the mean, so 68% of values are between 135 and 165. This means that 32% of values are not between those values. A normal distributuion is symmetric, so 16% of values are greater than 1 standard distribution and 16% are less. Therefore, 16% of values (160) are less than 135 and 16% of values (160) are greater than 165

Answer:

No it cant

Step-by-step explanation:

You have to use the Pythagoras theorem which is a^2 + b^2 = c^2. So 9^2 + 11^2= 202. Then 17 is the hypotenuse so 17^2= 289. They are not equal so they are not.

Answer:

13

Step-by-step explanation:

< W = <V            Given

WV = 8              Given

XV = 13              Given

Find XW

In an isosceles triangle if you are given the length of one of the sides opposite one of the two equal angles, then the side opposite the other equal angle is equal to the given side.

In sort XV = 13. < V = <W   XW = 13

Answer:

I think it is 4

I am not sure about it

Answer:

$13.25

Step-by-step explanation:

Given data

Cost of game = $25

Markup= 6%

Let us find the total cost of the game

First, the markup cost

=6/100*25

=0.06*25

=$1.5

Now the total cost is

=25+1.5

=$26.5

So, each is expected to pay

=26.5/2

=$13.25

Answer:

8

Step-by-step explanation:

Divide 30 by 3.75 to get 8.

Hope that this helps!

Answer:

yuh?

and what help do you need from me?

im a math genius, thank you very much

:)

Answer:

The discount is $0.8d.

Step-by-step explanation:

Given that,

The original cost of Tamara's purchase is d dollars​.

Tamara uses a coupon to save 20% off her purchase at the bookstore.

Discount = 20%

Discount is applied to the original cost.

Discount = d-(20/100)d

Discount = 0.8 d

Hence, the discount is $0.8d.

Answer:

20,100

Step-by-step explanation:

hundreds place is the third from the right

Answer:

20,100

Step-by-step explanation:

085 represents 0 hundreds, 8 tens and 5 ones.

That place keeper 0 is rounded  up to a 1 because the following '8' is greater than 5.

Thus, the desired rounded off number is 20,100.

Answer:

Step-by-step explanation:

∠EMC  = ∠EMD + ∠DMC

∠EMC = 90

∠EMD + ∠DMC = 90

∠EMD + 20 =90

∠EMD  = 90 - 20

∠EMD  = 70

∠FMD + ∠DMB = 180  {Linear pair}

90 + ∠DMB = 180

        ∠DMB = 180 - 90

       ∠DMB = 90

Answer:

a. 5 loaves, b. 14 loaves

Step-by-step explanation:

a.8.50=2.50+1.20x

  6.00=1.20x

  5=x

5 loaves

b.20=2.50+1.20x

   17.50=1.20x

   14.6=x

14 loaves

10.) x-23=-3x+5

x+3=5+23

4x=28

12.) -4ab+5-(-2ab + 3)

-4ab+5+2ab-3

13.) (-3)+(-5)

-3 -5

Answer:

The x-intercept = -3/2

Step-by-step explanation:

Set y = 0 to find the x-intercepts;

=> y = 4x + 6

=> 0 = 4x + 6

=> 0 - 6 = 4x

=> -6 = 4x

=> -6/4 = x

=> -3/2 = x

Therefore the x-intercept = -3/2

Hope this helps!

Answer:

Step-by-step explanation:

Since we are finding the x-intercepts, that implies that this is a parabola that opens either up or down as opposed to right or left. It would benefit us to know the equation of the parabola so we could factor it to find the roots (which are also known as the x-intercepts).

Here's what we know:

h = 1, k = 20, x = 0, and y = 20. Filling in the vertex form of a parabola is already halfway to factored, so we'll use that format as opposed to the standard form, which is

[tex]y=ax^2+bx+c[/tex]. The vertex form is

[tex]y=a(x-h)^2+k[/tex] and filling in our values from above:

[tex]16=a(0-1)^2+20[/tex] and

[tex]16=a(1)+20[/tex] and

-4 = a. So the equation for the parabola is

[tex]y=-4(x-1)^2+20[/tex]. Now set it equal to 0 and factor.

[tex]-20=-4(x-1)^2[/tex] and divide both sides by -4 to get:

[tex]5=(x-1)^2[/tex] and take the square root of both sides to get

±[tex]\sqrt{5}=x-1[/tex] and then add 1 to both sides to get the x-intercepts (or roots or solutions or zeros...they're all the same).

x = 1 ±√5 and you're done!

Answer:

range = 10

Step-by-step explanation:

The range is the difference between the largest and smallest values in the data set.

largest value = 12

smallest value = 2

range = 12 - 2 = 10

Answer:y< 3x + 12

y> 5x + 7

Step-by-step explanation:

Answer:

V =128 pi

Step-by-step explanation:

The volume of the cylinder is given by

V = pi r^ h

V = pi 4^2 *8

V = pi *16*8

V =128 pi