-
Is it c, because the center of the circle is fixed at a distance of 1 from the straight line y=3 on y=2So when the shortest radius is the shortest chord length, the shortest radius is 2 (obtained by the formula on both sides of the equation), so the chord length is 2 times the square of 2 under the root number minus 1 to get c
-
Circle: x 2+y 2-2mx-4y+4m-4=0, which is reduced to the standard equation of a circle, yields: (x-m) 2+(y-2) 2=(m-2) 2+4.
The center of the circle is: (m,2), on the straight line: y=2;
The radius of the circle r,r= [m-2) 2+4].
The straight line: y=2, the distance from the straight line y=3 is 1, the chord length of the straight line y=3 is rounded: 2 (r 2-1), the shortest, then: r 2=(m-2) 2+4, the smallest;
And [(m-2) 2+4>=4, so the minimum value of r 2 is: 4.
The shortest chord length is: 2 3.
Therefore, C.
-
g(x)=-x²-3
f(x) quadratic function, f(x) + g(x) odd function.
Because if there are quadratic terms and constant terms, it cannot be an odd function.
So f(x)=x+ax+3
In this case, f(x) + g(x) = ax odd function.
min=1 when x [-1,2].
The axis of symmetry x=-a 2 is discussed on the left and right sides of the interval and in the interval to obtain a=2 or a=-2 2
f(x)=x +2x+3 or f(x)=x -2 2x+3
-
1.The problem of finding inequalities.
That is, find the range of x values when -x is 2-5 > 1-5x.
2.Draw your own axes.
Then b calculates the range of values with .
It can be seen from the coordinate axes.
3.It is divided into several areas.
When 2>x>-3.
When x>2.
When x<-3 are discussed separately.
-
lzI'm also a freshman in high school.,It's better to do it yourself、、、 otherwise you'll suffer.。。
-
Step 1: Solve the equation of the parabola y=x5 and the straight line y=1 5x to find x1=2, x2=3
Step 2: Draw an image of the parabola y=x5 straight line, y=1 5x, and the two images intersect in the x1=2 and x2=3 directions. The parabolic opening is downward.
It was learned in 2The point on the parabola y=x5 in the range of
-
2) Solution: Obtained from the known.
Because aub=, a=
So x in b is greater than or equal to -1
Because a=, anb=
So b in x 3
So x=3 and x=-1 are solutions to x2+ax+b=0] obtained by Vinda's theorem.
a=2,b=-3
-
Question 1 2 Question 2 A = -1
b=-6 I don't know the third question.
-
1.According to the title, -x 2-5>1-5x, find 22According to the problem, -2 and 3 are the roots of the equation x 2+ax+b=0, and we find a=1 and b=-6
-
1 is equivalent to -x 2-5> 1-5x constant.
x^2-5x+6>0 x<2 or x>32.From the drawing of the inscription, we can know that b=
so b=-3, a=-2
3.Due to |x+3|-|x-2|>=-|(x+3)-(x-2)|=-5 Deformation of trigonometric inequalities.
So a<-5
-
1. 1-5x+x^2+5<0
then x 2-5x+6<0
x-2)(x-3)<0
2-2}, then the other root intersects a at the same time between the interval (-2, -1) b={x|1a
Discussion, x<=-3, primitive=-5
32, original = 5
For the equation to hold, a<-5
-
1.What is the value of x, where the point on the parabola y=-x 2-5 is above the line y=1-5x?
Analysis: 1-5x=-x 2-5==> x 2-5x+6=0==>x1=2,x2=3
At x (2,3), the point on the parabola y=-x 2-5 is above the straight line y=1-5x (on the right).
2.Let a=, b=, aub=, a intersect b=, aub=, a intersect b={x|1a-b=1 (1)
a+√(a^2-4b)]/2=3==>3a+b=-9 (2)
1) (2) The simultaneous solution yields a=-2 and b=-3
3.If for any real number x, |x+3|-|x-2|> a has a solution, and the range of values of the real number a is obtained.
Let the function f(x) = |x+3|-|x-2|
When x (-3], f(x) = -x-3+x-2=-5
When x (-3,2), f(x) = x+3+x-2=2x+1
When x[2,+,f(x)=x+3-x+2=5
If for any real number x, |x+3|-|x-2|> A has a solution, then A <-5
-
The topic is not clear, the root number ends at the end of the **? And how can there be a decimal under the root number?
-
a(-1,-1),b(-4,2)
Vector ab=(-3,3).
Vector ap|=(1/3)|Vector ab|
Vector ap=(1 3) vector ab=(-1,1)a(-1,-1).
p(-2,0)
c(3,0), point q is the midpoint of the line segment pc.
q(1/2,0)
-
Calculate the coordinates of p with the formula of the fixed score point, and then divide p+c by 2 to complete. There are two solutions. The formula is a compulsory four-vector for turning the book yourself.
x=(x1+λx2)/(1+λ)y=(y1+λy2)/(1+λ)
-
f(x) is an even function defined on r.
f(-x)=f(x)
x[f(x)+f(-x)]<0
2xf(x)<0
x<0,f(x)>0
then x -3x 0, f(x) 0
then 0 x 3
So the solution set is.
-
Hello, the ranges are (-infinity, -3) and (0,3).
One. Consider the function f(x)=x+4 x
f(x1)-f(x2)=(x1x2-4)(x1-x2)/(x1x2)0f(x2) >>>More
From the known results, -1 is less than or equal to x+1 less than or equal to 1, and the solution is that 2 is less than or equal to x and less than or equal to 0 >>>More
1 The equation for one axis of symmetry for the image of the function y=sin(2x+5 2 ) is ( >>>More
Let the two roots be respectively, then x1+x2=-1 So at least one of the two roots is negative, if one element is a non-negative number, then x1 times x2 is equal to a less than or equal to 0, which is the solution to this problem. >>>More
Question 16: a1 + a1 + 2d = 6, a1 + 3d + a1 + 5d = 18, so a1 = 1, d = 2, the first five terms are: , which add up to 25 >>>More