Answer:
Step-by-step explanation:
delta=( m-3)^2+4*5
pt có 2 nghiệm x1 x2 khi delta>0<=>(m-3)^2+20>0(luôn đúng)
Viet: x1+x2=3-m
x1x2=-5
x1^{2} +x2^{2} -5x1x2+3x1+3x2=4
<=>(x1+x2)^{2}-7x1x2+3(x1+x2)=4
<=>(3-m)^2+35+3*(3-m)=4
<=>m^2-6m+9+35-3m+9-4=0
<=>m^2-9m+49=0
Answer:
x = 60°
Step-by-step explanation:
Use special triangles.
Starting with an equilateral triangle (all angles at 60°) with the side length of 2. Drop an altitude from one of the vertices to cut in half and make a right - triangle.
The hypotenuse length is 2. The base length, because it was cut in half, is 1. The height can be found with the Pythagorean theorem, which is √3.
The ratio for tangent is opposite over adjacent.
Since √3 = √3 / 1, the angle must be the one as marked in the picture.
Remember this triangle came from an equilateral triangle, so that angle is 60°. It was not cut in half, unlike the top angle which is 30°.
Given:
A circle with radius 7 units and chord CD = 7 units.
To find:
The measure of arc CD.
Solution:
Let O be the center of the circle.
In triangle OCD,
(Given)
(Radii of same circle)
(Given)
Since
all sides are equal, therefore, the triangle OCD is an equilateral triangle.
Measure of each angle of an equilateral triangle is 60 degrees. So,

The measure of central angle is equal to the measure of corresponding arc.


Therefore, the measure of arc CD is 60 degrees.
Answer:
top left
Step-by-step explanation:
take a vertical line and place it on the graph. Then no matter where on the graph you place the vertical line, the graph should only cross the vertical line once. ( it only crossed once)