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3 years ago

Cos(x/3)cos(x/3)=1/2(1+cos(2x/3))

Mathematics

2 answers:

TEA [102]3 years ago

6 0

This follows from the half-angle identity for cosine.

$\cos^2\theta=\dfrac{1+\cos2\theta}2$

aleksklad [387]3 years ago

4 0

Answer:

it's true, don't have a step by step explanation just did it on my test.

Step-by-step explanation:

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Find all complex solutions of 7x^2-7x+3=0

Sedaia [141]

Answer:

The complex solutions are

$x = (\frac{7-\sqrt{35} i }{42} , ) x = \frac{7 + \sqrt{35} i }{42})$

Step-by-step explanation:

Step(i):-

Given equation 7 x² - 7 x +3=0

$x = (\frac{-b -\sqrt{b^{2}-4ac } }{2ac} , \frac{-b +\sqrt{b^{2}-4ac } }{2ac})$

Given standard equation

a x² +b x +c =0

a = 7 , b= -7 and c=3

Step(ii):-

$x = (\frac{-(-7) -\sqrt{(-7)^{2}-4(7)(3) } }{2(7)(3)} , \frac{-(-7) +\sqrt{(-7)^{2}-4(7)(3) } }{2(7)(3)})$

$x = (\frac{7-\sqrt{(49-84 } }{42} , \frac{7 +\sqrt{(49-84 } }{42})$

$x = (\frac{7-\sqrt{35i^{2} } }{42} , \frac{7 + \sqrt{35i^{2} } }{42})$

$x = (\frac{7-\sqrt{35} i }{42} , \frac{7 + \sqrt{35} i }{42})$

8 0

2 years ago

A line has a slope of -2 and passes through the point (3, 1). What is the equation of this line in slope-intercept form?

Zepler [3.9K]

Question 7. y = -2x + 7. y = mx + b; m= slope (-2) (3, 1) resolve for y. you have : 1= -2 (3) + b; 1 = -6 + b; 1 + 6 = b; b = 7.

6 0

3 years ago

Help on college algebra, question is on the picture!

kodGreya [7K]

$\frac{7x+1}{x-2} + \frac{2}{x} = \frac{-4}{ x^{2} -2x}$ is given
here , $\frac{7x+1}{x-2} + \frac{2}{x} = \frac{-4}{ x^{2} -2x}$
or, $\frac{7x^{2} +x +2x-4 }{x(x-2)} = \frac{-4}{ x^{2} -2x}$
or, $\frac{7 x^{2} +3x-4}{ x^{2} -2x} = \frac{-4}{ x^{2} -2x}$
or,7x²+3x-4=-4
or,7x²+3x=0
or,x(7x+3)=0
Either,x=0| Or,7x+3=0
|or,7x=-3
|or,x= $\frac{-3}{7}$
So , the solution set is S={0,- $\frac{3}{7}$ }

8 0

3 years ago

A biker travels at a rate of 20 miles per hour. Calculate

kow [346]

Answer:

60 miles

Step-by-step explanation:

20 miles times 3

3 0

3 years ago

Read 2 more answers

(5,12) with a slope m=10 the equation of the line is

motikmotik

Answer:

y= 10x-38

Step-by-step explanation:

Equation of a line is usually written in the form of y=mx+c, where m is its gradient and c is its y-intercept.

Given that m=10,

y= 10x +c

Now substitute the coordinates into the equation.

When y=12, x=5,

12= 10(5) +c

12= 50 +c

c= 12 -50

c= -38

Thus the equation of the line is y= 10x -38

8 0

3 years ago