Answer: The length of the rectangle is 35 in.

The width of the rectangle is 28 in.
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Explanation:
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The formula for the area, "A", of a rectangle:

Area (A) = length (L) * width (w) ;

that is: " A = L * w " ;

A = 980 in² (given);

ratio of the length to the width is: " 5 : 4 " (given);

→ Find the length (L) and the width (w).
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→ 980 in² = (5x) * (4x) ;

in which: " 980 in² " is the area of the triangle;

" 5x" = the length (L) of the rectangle, for which we shall solve;

" 4x" = the width (w) of the rectangle, for which we shall solve.
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If we find solve for "x" ; we can solve for "5x" and "4x" (the "length" and the "width", respectively); by plugging in the solved value for "x" ;
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→ 980 in² = (5x) * (4x) ;

↔ (5x) * (4x) = 980 in² ;

→ (5x) * (4x) = (5) * (4) * (x) * (x) = 20 * x² = 20x² ;

→ 20x² = 980 ;

Divide each side by "10" ; by canceling out a "0" on each side of the equation:

→ 2x² = 98 ;

Now, divide each side of the equation by "2" ;

→ 2x² / 2 = 98 / 2 ;

to get:

→ x² = 49 ;

Now, take the "positive square root" of each side of the equation; (since a "length or width" cannot be a "negative value") ;
to isolate "x" on one side of the equation; & to solve for "x" ;

→ ⁺√(x²) = √49 ;

to get:

→ x = 7 ;
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Now, we can solve for the "length" and the "width" ;

→ The length is: "5x" ;

5x = 5(7) = " 35 in " ;
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→ The width is: "4x" ;

4x = 4(7) = "28 in."
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Let us check our answer:

→ A = L * w ;

→ 980 in² = ? 35 in. * 28 in. ?? ;

Using a calculator: "35 * 28 = 980" . Yes! ;
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{ Also note: " in * in = in² " ? Yes! } .
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3 0

2 years ago

Please Help! This is a trigonometry question.

liraira [26]

$\large\begin{array}{l} \textsf{From the picture, we get}\\\\ \mathsf{tan\,\theta=\dfrac{2}{3}}\\\\ \mathsf{\dfrac{sin\,\theta}{cos\,\theta}=\dfrac{2}{3}}\\\\ \mathsf{3\,sin\,\theta=2\,cos\,\theta}\qquad\mathsf{(i)} \end{array}$

$\large\begin{array}{l} \textsf{Square both sides of \mathsf{(i)} above:}\\\\ \mathsf{(3\,sin\,\theta)^2=(2\,cos\,\theta)^2}\\\\ \mathsf{9\,sin^2\,\theta=4\,cos^2\,\theta}\qquad\quad\textsf{(but }\mathsf{cos^2\theta=1-sin^2\,\theta}\textsf{)}\\\\ \mathsf{9\,sin^2\,\theta=4\cdot (1-sin^2\,\theta)}\\\\ \mathsf{9\,sin^2\,\theta=4-4\,sin^2\,\theta}\\\\ \mathsf{9\,sin^2\,\theta+4\,sin^2\,\theta=4} \end{array}$

$\large\begin{array}{l} \mathsf{13\,sin^2\,\theta=4}\\\\ \mathsf{sin^2\,\theta=\dfrac{4}{13}}\\\\ \mathsf{sin\,\theta=\sqrt{\dfrac{4}{13}}}\\\\ \textsf{(we must take the positive square root, because }\theta \textsf{ is an}\\\textsf{acute angle, so its sine is positive)}\\\\ \mathsf{sin\,\theta=\dfrac{2}{\sqrt{13}}} \end{array}$

________

$\large\begin{array}{l} \textsf{From (i), we find the value of }\mathsf{cos\,\theta:}\\\\ \mathsf{3\,sin\,\theta=2\,cos\,\theta}\\\\ \mathsf{cos\,\theta=\dfrac{3}{2}\,sin\,\theta}\\\\ \mathsf{cos\,\theta=\dfrac{3}{\diagup\!\!\!\! 2}\cdot \dfrac{\diagup\!\!\!\! 2}{\sqrt{13}}}\\\\ \mathsf{cos\,\theta=\dfrac{3}{\sqrt{13}}}\\\\ \end{array}$

________

$\large\begin{array}{l} \textsf{Since sine and cosecant functions are reciprocal, we have}\\\\ \mathsf{sin\,2\theta\cdot csc\,2\theta=1}\\\\ \mathsf{csc\,2\theta=\dfrac{1}{sin\,2\theta}\qquad\quad\textsf{(but }}\mathsf{sin\,2\theta=2\,sin\,\theta\,cos\,\theta}\textsf{)}\\\\ \mathsf{csc\,2\theta=\dfrac{1}{2\,sin\,\theta\,cos\,\theta}}\\\\ \mathsf{csc\,2\theta=\dfrac{1}{2\cdot \frac{2}{\sqrt{13}}\cdot \frac{3}{\sqrt{13}}}} \end{array}$

$\large\begin{array}{l} \mathsf{csc\,2\theta=\dfrac{~~~~1~~~~}{\frac{2\cdot 2\cdot 3}{(\sqrt{13})^2}}}\\\\ \mathsf{csc\,2\theta=\dfrac{~~1~~}{\frac{12}{13}}}\\\\ \boxed{\begin{array}{c}\mathsf{csc\,2\theta=\dfrac{13}{12}} \end{array}}\qquad\checkmark \end{array}$

If you're having problems understanding this answer, try seeing it through your browser: brainly.com/question/2150237

$\large\textsf{I hope it helps.}$

Tags: trigonometry trig function cosecant csc double angle identity geometry

8 0

3 years ago

4. Evaluate the expression for the given value of each variable.

Novosadov [1.4K]

Answer:

-18

Step-by-step explanation:

5a2-7-b3

$5*a*2-7-b*3$

$5\cdot \left(-2\right)\cdot \left(2\right)-7-\left(-3\right)\cdot 3$

Therefore, -18 is your answer.

Hope this helped! :)

5 0

3 years ago