X² + 9x +22 = 0 anyone know what this is

Jlenok [28]

Answer:

Step-by-step explanation:

4 0

2 years ago

The angle θ lies in Quadrant II. sinθ=3/4 What is cosθ ?

Elden [556K]

Hello from MrBillDoesMath

Answer:

[email protected] = - sqrt(7)/ 4

which is choice B

Discussion:

This problem can be solved by drawing triangles and looking at ratios of sides or by using the trig identity:

([email protected])^2 + (sin2)^2 = 1

If [email protected] = 3/4 , the

([email protected])^2 + (3/4)^2 = 1 => (subtract (3/4)^2 from both sides)

([email protected])^2 = 1 - (3/4)^2 = 1 - 9/16 = 7/16

So...... taking the square root of both sides gives

[email protected] = +\- sqrt(7)/ sqrt(16) = +\- sqrt(7)/4

But is [email protected] positive or negative? We are told that @ is in the second quadrant and cos(@) is negative in this quadrant, so our answer must be negative

[email protected] = - sqrt(7)/ 4

which is choice B

Thank you,

Mr. B

4 0

3 years ago

What are the coordinates of the vertex for f(x) = 2x2 + 4x + 9?

Vlada [557]

Your equation $f(x)=2x^2+4x+9$ is in the form $y=ax^2+bx+c$
The vertex only relies on "a" and "b" though, so that +9 doesn't really matter in this case. The vertex of a parabola is located where
$x=\frac{-b}{2a}=\frac{-4}{2(2)}=-1$
So your x-coordinate is -1. You need to find f(-1) to find your y-coordinate, and then you list it in the form (-1, y).

5 0

2 years ago

Read 2 more answers

PLEASE HELP

irina [24]

Answer:

$12\sqrt{3}$ feet

Step-by-step explanation:

In a 30-60-90 triangle, the ratios of the side lengths of the triangle is $1:\sqrt{3} :2$

Where 1 is the shortest leg, root(3) is the longer leg, and 2 is the hypotenuse.

First we can set x equals to the length of the original pole, and so the shorter leg has a length of x/3 and using the ratio of side lengths, we can find that:

$\frac{x}{3} * \sqrt{3} = \frac{\sqrt{3} x}{3} = 12$