Simplify the expression sin 2x+ sin x + cos2x

Write an equation (a) in slope-intercept form and (b) in standard form for the line passing through (-3,5) and parallel to x + 4

Dmitry [639]

Answer:

$\boxed{\sf Standard-form :x + 4y -17=0 }\\$

$\boxed{\sf Slope-intercept\ form :y =\dfrac{-1}{4}x +\dfrac{17}{4}}$

Step-by-step explanation:

Here a equation of the line is given to us and we need to find out the equation of line which passes through the given point and parallel to the given line , the given equation is ,

$\longrightarrow x + 4y = 7\\$

Firstly convert it into slope intercept form of the line which is y = mx + x , as ;

$\longrightarrow 4y = -x + 7 \\$

$\longrightarrow y =\dfrac{-x}{4}+\dfrac{7}{4}\\$

On comparing it to y = mx + c , we have ,

$\longrightarrow m =\dfrac{-1}{4}\\$

$\longrightarrow c =\dfrac{7}{4}\\$

Now as we know that the slope of two parallel lines is same . Therefore the slope of the parallel line will be ,

$\longrightarrow m_{||)}=\dfrac{-1}{4}\\$

Now we may use point slope form of the line as ,

$\longrightarrow y - y_1 = m(x-x_1) \\$

On substituting the respective values ,

$\longrightarrow y - 5 =\dfrac{-1}{4}\{ x -(-3)\}\\$

$\longrightarrow y -5=\dfrac{-1}{4}(x+3)\\$

$\longrightarrow 4(y -5 ) =-1(x +3) \\$

$\longrightarrow 4y -20 = - x -3 \\$

$\longrightarrow x + 4y -20+3=0\\$

$\longrightarrow \underset{Standard \ Form }{\underbrace{\underline{\underline{ x + 4y -17=0}}}} \\$

Again the equation can be rewritten as ,

$\longrightarrow y - 5 = \dfrac{-1}{4}(x +3) \\$

$\longrightarrow y = \dfrac{-1}{4}x -\dfrac{3}{4}+5 \\$

$\longrightarrow y = \dfrac{-1}{4}x -\dfrac{20-3}{4} \\$

$\longrightarrow \underset{Slope-Intercept\ form }{\underbrace{\underline{\underline{ y =\dfrac{-1}{4}x +\dfrac{17}{4}}}}}\\$

6 0

2 years ago

find an equation in the form y=ax^2+bx+c for the parabola passing through the points. (2,28),(4,116),(-3,88)

IgorC [24]

<h3>Answer:</h3>

y = 8x² -4x +4

<h3>Explanation:</h3>

I find it quick and easy to let a graphing calculator do quadratic regression on the given points. It gives the coefficients of the equation directly. (See attached.)

_____

If you want to do this "by hand," you can substitute each of the x and y value pairs into the equation to get three linear equations in a, b, and c. These are generally easy to solve, as the "c" variable can be eliminated right away.

For x = 2

... 28 = a·2² +b·2 +c = 4a +2b +c

For x = 4

... 116 = a·4² +4b +c = 16a +4b +c

For x = -3

... 88 = a·(-3)² +b·(-3) +c = 9a -3b +c

Subtracting the first and third equations from the second, we have ...

... (16a +4b +c) -(4a +2b +c) = (116) -(28) ⇒ 12a +2b = 88

... (16a +4b +c) -(9a -3b +c) = (116) -(88) ⇒ 7a +7b = 28

Dividing the first of these reduced equations by 2, and the second by 7, we have ...

6a +b = 44
a +b = 4

Subtracting the second of these from the first gives ...

... (6a +b) -(a +b) = (44) -(4) ⇒ 5a = 40

From which we find

... a = 8

... b = 4 -a = 4 -8 = -4

We choose the first of the original equations to find c:

... c = 28 -4a -2b = 28 -4·8 -2(-4)

... = 28 -32 +8 = 4

With (a, b, c) = (8, -4, 4), the equation of the parabola is ...

... y = 8x² -4x +4

5 0

3 years ago

Which expression below are equivalent to 2(2x + 1)

emmainna [20.7K]

Answer:

4x+2

Step-by-step explanation:

you are doing distributive property so the answer could possibly be: 4x+2

7 0

3 years ago

Avery uses a blend of dark chocolate and milk chocolate to make the ice cream topping at her restaurant. She wants to buy 10 kg

Ksju [112]

Answer:

$d = m + 10\\d+m=150$

Step-by-step explanation:

If Avery wants the amount of dark chocolate (d) to be 10 kg higher than the amount of milk chocolate (m), then the following relationship must be true:

$d = m + 10$