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3 years ago

Find the value of 2cosx+1=0;0 less than x less than 360°

Mathematics

1 answer:

ohaa [14]3 years ago

7 0

Answer:

120°; 240°

Step-by-step explanation:

Let's first solve for $cosx$ : $2cosx=-1 \rightarrow cosx=-\frac12$ At this point it's just a matter of drawing a circle, and mark where the angle is(please excuse my paint skills, but free hand drawing would be even worse). Red line, is $-\frac12$ on the cosines, and both the green and blue lines are valid solutions. The green line is a quarter of a circle, plus 30°, or 120°. The blue one is 3/4 of a circle, minus 30 degrees, or 240°.

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What is 17 divided by 3 without remainders.

LenaWriter [7]

Answer:

5.6666666667

Step-by-step explanation:

that is 17 divided by three without remainders

4 0

3 years ago

Read 2 more answers

A quadrilateral has vertices at A(–5, 5), B(1, 8), C(4, 2), D(–2, –2). Use slope to determine if the quadrilateral is a rectangl

lianna [129]

With the properties of rectangle in mind we must perform two verification. Verify to see if opposite sides are parallel and adjacent sides are perpendicular.

We need to determine the slope of each side, using the formula,

$m=\frac{y_2-y_1}{x_2-x_1 }$

Slope of AB

$m_{AB}=\frac{8-5}{1--5}$

$\Rightarrow m_{AB}=\frac{8-5}{1+5}$

$\Rightarrow m_{AB}=\frac{3}{6}$

$\Rightarrow m_{AB}=\frac{1}{2}$

Slope of BC

$m_{BC}=\frac{2-8}{4-1}$

$\Rightarrow m_{BC}=\frac{-6}{3}$

$\Rightarrow m_{BC}=-2$

Slope of CD

$m_{CD}=\frac{-2-2}{-2-4}$

$\Rightarrow m_{CD}=\frac{-2-2}{-2-4}$

$\Rightarrow m_{CD}=\frac{-4}{-6}$

$\Rightarrow m_{CD}=\frac{2}{3}$

Slope of AD

$m_{AD}=\frac{-2-5}{-2--5}$

$\Rightarrow m_{AD}=\frac{-2-5}{-2+5}$

$\Rightarrow m_{AD}=\frac{-7}{3}$

Verify Parallel sides

If the quadrilateral is a rectangle, then opposite sides should have the same slope. But

$m_{AD} = \frac{-7}{3} \neq m_{BC}=-2$

$m_{AB}=\frac{1}{2} \neq m_{CD}=\frac{2}{3}$

Verify Perpendicularity

And also the product of slopes of all sides with a common vertex should be -1. But

$m_{AB} \times m_{BC}=\frac{1}{2} \times -2=-1$

$m_{AB} \times m_{AD}=\frac{1}{2} \times -\frac{7}{3} \neq -1$

$\Rightarrow m_{CD} \times m_{AD}=\frac{2}{3} \times -\frac{7}{3} \neq -1$

$\Rightarrow m_{CD} \times m_{BC}=\frac{2}{3} \times -2 \neq -1$

Since the quadrilateral fails to satisfy all these conditions, the quadrilateral is not a rectangle

6 0

3 years ago

Josh needs to wash 4 plates, 12 pieces of silverware, and 4 cups. Then he needs to dry them all. How many items will he touch, i

geniusboy [140]

Answer:

40 times.

Step-by-step explanation:

4+4+12=(20 x 2)=40

5 0

3 years ago

Write an equation for an ellipse centered at the origin, which has foci at (0,\pm\sqrt{63})(0,± 63 )left parenthesis, 0, comma

steposvetlana [31]

Answer:

$\frac{x^{2} }{4312 } + \frac{y^{2} }{8281 }$

Step-by-step explanation:

Since the foci are at(0,±c) = (0,±63) and vertices (0,±a) = (0,±91), the major axis is the y- axis. So, we have the equation in the form (with center at the origin) $\frac{x^{2} }{b^{2} } + \frac{y^{2} }{a^{2} }$ .