Answer:
Step-by-step explanation:
<h3>Given </h3>
<h3>To find</h3>
<h3>Solution</h3>
- 5x:9=7:3
- 5x = 7*9/3
- 5x = 7*3
- 5x = 21
- x = 21/5
- x = 4.2
Taking

and differentiating both sides with respect to

yields
![\dfrac{\mathrm d}{\mathrm dx}\bigg[3x^2+y^2\bigg]=\dfrac{\mathrm d}{\mathrm dx}\bigg[7\bigg]\implies 6x+2y\dfrac{\mathrm dy}{\mathrm dx}=0](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dx%7D%5Cbigg%5B3x%5E2%2By%5E2%5Cbigg%5D%3D%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dx%7D%5Cbigg%5B7%5Cbigg%5D%5Cimplies%206x%2B2y%5Cdfrac%7B%5Cmathrm%20dy%7D%7B%5Cmathrm%20dx%7D%3D0)
Solving for the first derivative, we have

Differentiating again gives
![\dfrac{\mathrm d}{\mathrm dx}\bigg[6x+2y\dfrac{\mathrm dy}{\mathrm dx}\bigg]=\dfrac{\mathrm d}{\mathrm dx}\bigg[0\bigg]\implies 6+2\left(\dfrac{\mathrm dy}{\mathrm dx}\right)^2+2y\dfrac{\mathrm d^2y}{\mathrm dx^2}=0](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dx%7D%5Cbigg%5B6x%2B2y%5Cdfrac%7B%5Cmathrm%20dy%7D%7B%5Cmathrm%20dx%7D%5Cbigg%5D%3D%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dx%7D%5Cbigg%5B0%5Cbigg%5D%5Cimplies%206%2B2%5Cleft%28%5Cdfrac%7B%5Cmathrm%20dy%7D%7B%5Cmathrm%20dx%7D%5Cright%29%5E2%2B2y%5Cdfrac%7B%5Cmathrm%20d%5E2y%7D%7B%5Cmathrm%20dx%5E2%7D%3D0)
Solving for the second derivative, we have

Now, when

and

, we have
12 boys. 7 * 3 is 21. 21 girls. 4*3 is 12. 12 boys 21 girls
Answer:
x²/2166784 +y²/2159989 = 1
Step-by-step explanation:
The relationship between the semi-axes and the eccentricity of an ellipse is ...
e = √(1 -b²/a²)
In order to write the desired equation we need to find 'b' from 'e' and 'a'.
__
<h3>semi-minor axis</h3>
Squaring the equation for eccentricity gives ...
e² = 1 -b²/a²
Solving for b², we have ...
b²/a² = 1 -e²
b² = a²(1 -e²)
<h3>ellipse equation</h3>
Using the given values, we find ...
b² = 1472²(1 -0.056²) = 2166784(0.996864) ≈ 2159989
The desired equation is ...
x²/2166784 +y²/2159989 = 1
We are given an angle of 60° and a side of 15 cm.
We are given the opposite and is looking for the hypotenuse so we will use the sine ratio to find x.
sin = opp/hyp
hyp = 15 / sin 60
hyp = 17.32...
//
We can also use the tangent ratio to find the adjecent and then use pythagorean to find x.
tan = opp/adj
adj = 15 / tan 60
adj = 8.660.....
8.660....² + 15² = 300²
since the square root of 300 is an irrational number, we have to turn it into a mixed radical.
The answer would be the top one.