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maw [93]
2 years ago
10

Which of the following are solutions to the equation 2cos2x-1=0

Mathematics
1 answer:
loris [4]2 years ago
8 0

Answer:

x = π/4 and 5π/4

Step-by-step explanation:

Given the expression;

2cos²x - 1 = 0

2cos²x = 0+1

2cos²x = 1

cos²x = 1/2

cos x = ±√1/2

cos x = ±0.7071

x = arccos(±0.7071)

x = ±45 degrees

Convert to radians

Sence 180° = π rad

45°  = x

x = 45π/180

x = π/4

If x = -45°

Since cos is negative in the 3rd quadrant

x = 180 + 45

x = 225°

x = 225π/180

x = 45π/36

x = 5π/4

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Find the distance from point A(−9,−3) to the line y = x−6. Round your answer to the nearest tenth.
Vladimir79 [104]

The distance from point A(−9,−3) to the line y = x−6 is 8.5 units

<u>What is slope ?</u>

A line's steepness is determined by its slope. In mathematics, slope is determined by "rise over run" (change in y divided by change in x).

step 1

Find the slope of the perpendicular line to the given line

y=x-6 ---> given line

The slope is m=1

Remember that

If two lines are perpendicular, then their slopes are opposite reciprocal (the product of their slopes is equal to -1)

m1*m2 = -1

we have

m1=1

substitute

(1)*m2 = -1

so

m2 = -1

step 2

Find the equation of the perpendicular line to the given line

The equation in point slope form is

y-y1=m(x-x1)

we have

m=-1

(x1,y1)=(−9,−3)

substitute

y+3=-1(x+9)--> equation in point slope form

y+3= -x-9

y= -x-12---> equation in slope intercept form

step 3

Find the intersection point between the given line and the perpendicular line to the given line

we have the system of equations

y = x−6.

y= -x-12

Solve the system by graphing

The intersection point is (-3,-9)

see the attached figure

step 4

we know that

The distance between the point A and the point (-3,-9) is the same that the distance between point A and the line y=x-6

the formula to calculate the distance between two points is equal to

d=√[(y2-y1)² + (x2-x1)²]

substitute the values

d=√[(-9+3)² + (-3+9)²]

d= √72 units

simplify

d= 6√2 = 8.5 units

To learn more about the slope from the given link

brainly.com/question/16949303

#SPJ1

8 0
8 months ago
What is the slope of the graph of 8x – 4y = 11?
AlekseyPX
Y = mx + b
where m is the gradient (slope)
-4y = 11 - 8x
4y = 8x - 11
y = 2x - 11/4
m = 2

The correct answer is A.
7 0
3 years ago
Please thank youuu asap!!!!!!!!!!!!!!!!!
Vitek1552 [10]

All direct proportional graphs go through the origin (0,0). So this is where one point could go. The second point is found by going up 5 units and then to the right 3 units to get to (3,5)

<h3>Draw a straight line through (0,0) and (3,5) to graph</h3>

The equation of this line is y = (5/3)x

5 0
2 years ago
Kyle received the following course grades for 10​ (three-credit) courses during his freshman​ year:
timofeeve [1]

Answer:

(a) The average grade point is 2.5.

(b) The relative frequency table is show below.

(c) The mean of the relative frequency distribution is 0.3333.

Step-by-step explanation:

The given data set is

4, 4, 4, 3, 3, 3, 1, 1, 1, 1

(a)

The average grade point is

Average=\frac{\sum x}{n}

Average=\frac{4+4+4+3+3+3+1+1+1+1}{10}

Average=2.5

Therefore the average grade point is 2.5.

(b)

\text{Relative frequency}=\frac{\text{Frequency of number}}{\text{Total frequency}}

The relative frequency table is show below:

x                 f                  Relative frequency

4                3                 \frac{3}{10}=0.3

3                3                 \frac{3}{10}=0.3

1                 4                 \frac{4}{10}=0.4

(c)

Mean of the relative frequency distribution is

Average=\frac{0.3+0.3+0.4}{3}

Average=0.3333

Therefore the mean of the relative frequency distribution is 0.3333.

4 0
3 years ago
What is |9|? <br> -18<br> -9<br> 9<br> 18
Veseljchak [2.6K]

Answer:

the true answer is 9

Step-by-step explanation:

Because the product of the absolute value is the same number and positive

6 0
2 years ago
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