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4 years ago

HELP PLEASE!! THANK YOU!

Mathematics

1 answer:

dmitriy555 [2]4 years ago

3 0

Answer: choice B, 40.5 degrees

The triangle is isosceles based on the fact that AC = BC (the tick marks are the same). The angles opposite the congruent sides are also congruent

angle A = angle B = x for some unknown number x

The three angles A,B,C add to 180, so,

A+B+C = 180

x+x+99 = 180

2x+99 = 180

2x = 180-99

2x = 81

x = 81/2

x = 40.5

So angle A and angle B are both 40.5 degrees

Check:

A+B+C = 180

40.5+40.5+99 = 180

180 = 180 answer is confirmed

==============================

Edit

The sides with the two tick marks are the same length, so 7x-4 is the same as length as 31

7x-4 = 31

7x = 31+4

7x = 35

x = 35/7

x = 5

Answer is choice B) 5

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HELP I DONT UNDERSTAND CAN SOMEONE HELP

Rashid [163]

B

Do 450 x 2/5 (0.4 in decimal form)

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2 years ago

Find the area that the curve encloses and then sketch it.<br> r = 3 + 8 sin(6)

Rudiy27

Answer:

$A=41\pi\: \text{units}^2\approxA\approx128.8053\:\text{units}^2$

Step-by-step explanation:

I assume you mean $r=3+8\sin\theta$ :

Use the formula $\displaystyle A=\int\limits^a_b \frac{1}{2} {r(\theta)^2} \, d\theta$ where $a$ and $b$ are the lower and upper bounds and $r(\theta)$ is the equation of the polar curve.

Since the graph is symmetrical about the line $\displaystyle \theta=\frac{\pi}{2}$ , let the bounds of integration be $\displaystyle \biggr(-\frac{\pi}{2},\frac{\pi}{2}\biggr)$ to find half the area of the curve, and then find twice of that area:

$\displaystyle A=\int\limits^a_b \frac{1}{2} {r(\theta)^2} \, d\theta\\\\A=2\int\limits^{\frac{\pi}{2}}_{-\frac{\pi}{2}} \frac{1}{2} {(3+8\sin\theta)^2} \, d\theta\\\\A=\int\limits^{\frac{\pi}{2}}_{-\frac{\pi}{2}} 9+48\sin\theta+64\sin^2\theta \, d\theta\\\\A=\int\limits^{\frac{\pi}{2}}_{-\frac{\pi}{2}} 9+48\sin\theta+64\biggr(\frac{1-\cos2\theta}{2} \biggr) \, d\theta\\\\\\A=\int\limits^{\frac{\pi}{2}}_{-\frac{\pi}{2}} (9+48\sin\theta+32-32\cos2\theta) \, d\theta$

$\displaystyle A=\int\limits^{\frac{\pi}{2}}_{-\frac{\pi}{2}} (41+48\sin\theta-32\cos2\theta) \, d\theta\\\\A=41\theta-48\cos\theta-16\sin2\theta\biggr|^{\frac{\pi}{2}}_{-\frac{\pi}{2}}\\\\$

$A=\biggr[41\biggr(\frac{\pi}{2}\biggr)-48\cos\biggr(\frac{\pi}{2}\biggr)-16\sin2\biggr(\frac{\pi}{2}\biggr)\biggr]-\biggr[41\biggr(-\frac{\pi}{2}\biggr)-48\cos\biggr(-\frac{\pi}{2}\biggr)-16\sin2\biggr(-\frac{\pi}{2}\biggr)\biggr]\\\\A=\biggr[\frac{41\pi}{2}-24\sqrt{2}\biggr]-\biggr[-\frac{41\pi}{2}+24\sqrt{2}\biggr]\\ \\A=41\pi\\\\A\approx128.8053$

Thus, the area of the curve is 41π square units. See below for a graph of the curve and its shaded area.

7 0

3 years ago

X^2=1 has two solutions. If the equation is changed to 4x^2=1 which operation find the solutions of the new equation?

snow_lady [41]

Answer:

X = -1/2 or 1/2

Step-by-step explanation:

When the square root of a number is found, this usually results in 2 solutions which may be equal in size but opposite in signs.

As such,

X^2=1 to find x find the root of both sides

X = √1

X = -1 or 1

Going by this

4x^2=1

Divide both sides by 4

X^2=1 /4

taking the square root of both sides

X = √1/4

The root of 1 is -1 or 1 while that of 4 is -2 or 2 hence,

X = -1/2 or 1/2

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3 years ago

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konstantin123 [22]

The answer is B-about 18km

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then you round 13.94 to 14km

you add these rounded numbers together

you take it away from 50km

the answer would then me 18km

but it be ABOUT because that was only a rough estimate because it was rounded

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3 years ago

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fgiga [73]

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