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3 years ago

PLEASE HELP! URGENT. the law of cosines is a2+b2-2abcosC=c2. Find the value of 2abccosC.

Mathematics

1 answer:

Elodia [21]3 years ago

5 0

Answer:

Step-by-step explanation:

2ab*cos(C)=a^2+b^2-c^2

2ab*cos(C)=5^2+4^2-2^2=25+12=37

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2 years ago

Tyler made a scale drawing of a 24 ft long boat. In his drawing, the boat was 6 inches. The scale that Tyler used for his drawin

defon

Answer:

In Tyler scale, 1 inch equals 4 ft.

Step-by-step explanation:

Giving the following information:

Tyler made a scale drawing of a 24 ft longboat. In his drawing, the boat was 6 inches.

We know that 1 ft is 12 inches. Therefore, 24 ft:

24*12= 288 inches

Now, we have to determine the scale that Tyler used.

1 Tyler inch= 288/6= 48 inches

In ft:

1 Tyler inch= 48/12= 4 ft

In Tyler scale, 1 inch equals 4 ft.

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3 years ago

A rancher wants to fence in an area of 1500000 square feet in a rectangular field and then divide it in half with a fence down t

VLD [36.1K]

Answer:

6000 ft

Step-by-step explanation:

Let length of rectangular field=x

Breadth of rectangular field=y

Area of rectangular field= $1500000$ square ft

Area of rectangular field= $l\times b$

Area of rectangular field= $x\time y$

$1500000=xy$

$y=\frac{1500000}{x}$

Fencing used ,P(x)= $x+x+y+y+y=2x+3y$

Substitute the value of y

P(x)= $2x+3(\frac{1500000}{x})$

$P(x)=2x+\frac{4500000}{x}$

Differentiate w.r.t x

$P'(x)=2-\frac{4500000}{x^2}$

Using formula: $\frac{dx^n}{dx}=nx^{n-1}$

$P'(x)=0$

$2-\frac{4500000}{x^2}=0$

$\frac{4500000}{x^2}=2$

$x^2=\frac{4500000}{2}=2250000$

$x=\sqrt{2250000}=1500$

It is always positive because length is always positive.

Again differentiate w.r.t x

$P''(x)=\frac{9000000}{x^3}$

Substitute x=1500

$P''(1500)=\frac{9000000}{(1500)^3}>0$

Hence, fencing is minimum at x=1 500

Substitute x=1 500

$y=\frac{1500000}{1500}=1000$

Length of rectangular field=1500 ft

Breadth of rectangular field=1000 ft

Substitute the values

Shortest length of fence used= $2(1500)+3(1000)=6000 ft$

Hence, the shortest length of fence that the rancher can used=6000 ft

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4 years ago

7) Is -2 a zero (or root) of f(x) = 7x3 + x2 - 9x + 5?

Masja [62]

Answer:

Step-by-step explanation:

i do not know

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3 years ago