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2 years ago

Q11.

Mathematics

1 answer:

Kamila [148]2 years ago

5 0

Answer:

Step-by-step explanation:

The area of a trapezium is given as;

Area = $\frac{1}{2}$ (a + b)h

where: a is the length of the upper side, b is the length of its base and h is its height.

This implies that; a = x - 4, b = x + 5, h = 2x and area = 351

Thus,

351 = $\frac{1}{2}$ ((x - 4) + (x + 50)) 2x

= (x - 4 + x + 5) x

531 = (2x + 1) x

= 2 $x^{2}$ + x

So that;

2 $x^{2}$ + x - 531 = 0

This gives a quadratic equation.

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Find the equation of the tangent line to the curve (a lemniscate)

olya-2409 [2.1K]

Answer:

$m=\frac{9}{13}$ and $b=\frac{40}{13}$

Step-by-step explanation:

The equation of curve is

$2(x^2+y^2)^2=25(x^2-y^2)$

We need to find the equation of the tangent line to the curve at the point (-3, 1).

Differentiate with respect to x.

$2[2(x^2+y^2)\frac{d}{dx}(x^2+y^2)]=25(2x-2y\frac{dy}{dx})$

$4(x^2+y^2)(2x+2y\frac{dy}{dx})=25(2x-2y\frac{dy}{dx})$

The point of tangency is (-3,1). It means the slope of tangent is $\frac{dy}{dx}_{(-3,1)}$ .

Substitute x=-3 and y=1 in the above equation.

$4((-3)^2+(1)^2)(2(-3)+2(1)\frac{dy}{dx})=25(2(-3)-2(1)\frac{dy}{dx})$

$40(-6+2\frac{dy}{dx})=25(-6-2\frac{dy}{dx})$

$-240+80\frac{dy}{dx})=-150-50\frac{dy}{dx}$

$80\frac{dy}{dx}+50\frac{dy}{dx}=-150+240$

$130\frac{dy}{dx}=90$

Divide both sides by 130.

$\frac{dy}{dx}=\frac{9}{13}$

If a line passes through a points $(x_1,y_1)$ with slope m, then the point slope form of the line is

$y-y_1=m(x-x_1)$

The slope of tangent line is $\frac{9}{13}$ and it passes through the point (-3,1). So, the equation of tangent is

$y-1=\frac{9}{13}(x-(-3))$

$y-1=\frac{9}{13}(x)+\frac{27}{13}$

Add 1 on both sides.

$y=\frac{9}{13}(x)+\frac{27}{13}+1$

$y=\frac{9}{13}(x)+\frac{40}{13}$

Therefore, $m=\frac{9}{13}$ and $b=\frac{40}{13}$ .

5 0

2 years ago

The accompanying summary data on total cholesterol level (mmol/l) was obtained from a sample of Asian postmenopausal women who w

dimulka [17.4K]

Answer:

99% CI:

$-4.637\leq\mu_v-\mu_o\leq 3.737$

Step-by-step explanation:

We have to calculate a 99%CI for the difference of means for the vegan and the omnivore.

First, we have to estimate the standard deviation

$s_{Md}=\sqrt{\frac{2MSE}{n_h}}$

The MSE can be calculated as

$MSE=\frac{(SSE_1+SSE_2)}{df} =\frac{(n_1s_1)^2+(n_2*s_2)^2}{n_1+n_2-2}\\\\MSE=\frac{(85*1.05)^2+(96*1.20)^2}{85+96-2}=\frac{7965.56+13272.04}{179} =118.65$

The weighted sample size nh can be calculated as

$n_h=\frac{2}{1/n_1+1/n_2}=\frac{2}{1/85+1/96}=\frac{2}{0.0222} =90.16$

The standard deviation then becomes

$s_{Md}=\sqrt{\frac{2MSE}{n_h}}=\sqrt{\frac{2*118.65}{90.16}}=\sqrt{2.632} =1.623$

The z-value for a 99% confidence interval is z=2.58.

The difference between means is

$\Delta M=M_v-M_o=5.10-5.55=-0.45$

Then the confidence interval can be constructed as

$\Delta M-z*s_{Md}\leq\mu_v-\mu_o\leq \Delta M+z*s_{Md}\\\\ -0.45-2.58*1.623\leq\mu_v-\mu_o\leq -0.450+2.58*1.623\\\\-0.450-4.187\leq\mu_v-\mu_o\leq-0.450+4.187\\\\-4.637\leq\mu_v-\mu_o\leq 3.737$

8 0

2 years ago

Denise makes three times as many chocolate cupcakes as vanilla cupcakes. She also makes three dozen strawberry cupcakes. If Deni

slamgirl [31]

Answer:

6 dozens

Step-by-step explanation:

Vanilla, v = x

Chocolate, c = 3x

Strawberry, s = 3 dozens = 36

Total cupcakes = 132

Hence,

x + 3x + 36 = 132

4x = 96

x = 96 / 4

x = 24

Chocolate = 3 * 24 = 72

Dozens of chocolate = 72 /12 = 6 dozens

7 0

2 years ago

Solve the inequality 171>-6x and graph the solution what does the graph look like

krok68 [10]

To solve the inequality, you need to isolate/get x by itself:

171 > -6x Divide -6 on both sides [dividing/multiplying a negative number on

-28.5 < x [dividing/multiplying a negative number in an inequality causes the sign (<, >, ≤, ≥) to flip]

-28.5 < x [x is a number greater than -28.5]

So your graph should have an open circle at -28.5 (the first small line next to -28), and the arrow pointing to the right since x is greater than -28.5 (increasing) The 1st option is your answer

[use the o---> and put it at -28.5]

7 0

3 years ago

Convert 20 mile per hour to kilometers per liter

ElenaW [278]

Fuel Consumption Convert

≈ 8.5 kilometers per liter

7 0

2 years ago

Read 2 more answers