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VARVARA [1.3K]
3 years ago
14

what is the exact value of sin 22.5 degrees using the sum, difference, half, or double angle formulas and the exact value chart

in the solution.
Mathematics
1 answer:
AlexFokin [52]3 years ago
8 0
cos 2x=1-2sin^2x \\ cos 45^0=1-2sin^2(22,5)^0 \\  \frac{ \sqrt{2} }{2} =1-2sin^2(22,5)^0 \to sin(22,5)^0= \frac{ \sqrt{2- \sqrt{2} } }{2}
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Two numbers have a sum of 761 and a difference of 335.what are the 2 numbers ​
melisa1 [442]

Answer:

548 and 213

Step-by-step explanation:

Use a linear function:

Let x = 1st number

Let y = 2nd number

x+y=761

x-y=335

2x=1096

x=548

plug x into either equation

548+y=761

y=761-548

y=213

548-y=335

-y=-213

y=213

6 0
3 years ago
For the function f(x)=ax^3+bx^2-5x+9, determine the values of a and b so that f(-1)=12 and f'(-1)=3
Alecsey [184]

If

<em>f(x)</em> = <em>ax</em> ³ + <em>bx</em> ² - 5<em>x</em> + 9

then

<em>f '(x)</em> = 3<em>ax </em>² + 2<em>bx</em> - 5

Given that <em>f</em> (-1) = 12 and <em>f</em> '(-1) = 3, we get the system of equations

-<em>a</em> + <em>b</em> + 5 + 9 = 12

3<em>a</em> - 2<em>b</em> - 5 = 3

or

-<em>a</em> + <em>b</em> = -2

3<em>a</em> - 2<em>b</em> = 8

Multiply through the first equation by 2 and add it to the second one to eliminate <em>b</em> and solve for <em>a</em> :

2(-<em>a</em> + <em>b</em>) + (3<em>a</em> - 2<em>b</em>) = 2(-2) + 8

-2<em>a</em> + 2<em>b</em> + 3<em>a</em> - 2<em>b</em> = -4 + 8

<em>a</em> = 4

Substitute this into the first equation above to solve for <em>b</em> :

-4 + <em>b</em> = -2

<em>b</em> = 2

4 0
3 years ago
Which statement is true about the equations –3x + 4y = 12 and One-fourthx – One-thirdy = 1?
Rama09 [41]

Answer:

first one

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
Someone please help!!
mario62 [17]
Because l//m, s=n
k+p+n=180
So k+p+s=180
8 0
3 years ago
Which equation represents a parabola that has a focus of (0, 0) and a directrix of y = 4?
Ray Of Light [21]

Answer:

x2=−8(y−2)

Step-by-step explanation:

Parabola is a locus of a point which moves at the same distance from a fixed point called the focus and a given line called the directrix.

Let P(x,y) be the moving point on the parabola with  

focus at S(h,k)= S(0,0)  

& directrix at y= 4

Now,  

|PS| = √(x-h)2 + (y-k)2

|PS| = √(x-0)2 + (y-0)2

|PS| = √ x2 + y2

Let ‘d’ be the distance of the moving point P(x,y) to directrix y- 4=0

  •   d= |ax +by + c|/ √a2 + b2
  •   d= |y-4|/ √0 + 1
  •   d= |y-4| units.

equation of parabola is:  

  • |PS| = d
  • √ x2 + y2 = |y-4|

Squaring on both sides, we get:  

  • x2 + y2 = (y-4)2
  • x2 + y2 = y2 -8y + 16
  • x2 = - 8y + 16
  • x2 = -8 ( y - 2)  

This is the required equation of the parabola with focus at (0,0) and directrix at y= 4.

8 0
3 years ago
Read 2 more answers
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