The bottom of a parallelogram is 7.8cm, the height is 4.5cm, and its area is (), which is equal to its bottom The base of a parallelogram is 7.8cm, the height is 4.5cm, its area is (), and the triangle area with the same base and height is ()

The bottom of a parallelogram is 7.8cm, the height is 4.5cm, and its area is (), which is equal to its bottom The base of a parallelogram is 7.8cm, the height is 4.5cm, its area is (), and the triangle area with the same base and height is ()

27.3 13.65

8x+19=51

8x=51-19
8x=32
x=4

The tangent equation of curve y = x2-2x + 1 at point (1,0) is______ ．

The derivative of the curve y = x2-2x + 1 is y ′ = 2x-2, the tangent slope of the curve y = x2-2x + 1 at the point (1, 0) is 0, and the tangent equation is y = 0

How to solve 7x = (6x-18) + (x + 18)?

7x=（6x-18）+（x+18）
7x=6x-18+x+18
7x-6x-x=18-18
.0=0

Find the maximum value of the function y = (√ 1-x & # 178;) / (2 + x), let x = cos α. α ∈ [0, π], and then?

Let x = cos α. α ∈ [0, π], sin α > 0y = sin α / (2 + cos α) = (sin α - 0) / [cos α - (- 2)] be regarded as the slope of the line between the point (COS α, sin α) and the point (- 2,0). When plotting on the unit circle, the maximum slope is the root sign 3 / 3Y = (√ 1-x & # 178;) / (2 + x), and the maximum value is {0}

Nine times of a number and this number are reciprocal. What is this number?

Let this number be x.x × 9x = 1 & nbsp; 9x2 = 1 & nbsp; 3x = 1 & nbsp; & nbsp; X = 13 A: this number is 13

(1) If x and y are positive numbers, find the minimum value of (x + 1 / 2Y) ^ 2 + (y + 1 / 2x) ^ 2

（x+1/2y)^2+(y+1/2x)^2
=x^2+x/y+1/(4y^2)+y^2+y/x+1/(4x^2)
=x^2+1/(4x^2)+x/y+y/x++1/(4y^2)+y^2
>=2 * x * (1 / (2x)) + 2 * radical ((x / y) * (Y / x)) + 2 * y * (1 / (2Y))
=1+2+1=4
The condition of equal sign is that x = 1 / (2x), X / y = Y / x, y = 1 / (2Y) hold at the same time, that is, x = y = radical (2) / 2
So, when x = y = radical (2) / 2, (x + 1 / 2Y) ^ 2 + (y + 1 / 2x) ^ 2 gets the minimum value of 4

Let f (x) = ax ^ 2 + (B-8) x-a-ab be - 3 and 2 respectively
(1) Finding the analytic expression of function f (x)
(2) When the domain of function f (x) is [0,1], the range of F (x) is obtained

-3 and 2 are the two roots of the equation AX ^ 2 + (B-8) x-a-ab = 0
-(B-8) / a = - 3 + 2 = - 1 gives B-8 = a
(- a-Ab) / a = - 1-B = - 3 * 2 = - 6, the solution is b = 5; substituting the lion above, we can see that a = - 3
So f (x) = - 3x ^ 2-3x-12
two
F (x) = - 3 (x ^ 2 + X + 4) the axis of symmetry is x = - B / 2A = - 1 / 2, which is not in the interval [0,1], so the function is monotone in [0,1]
f（0）=-12 f(1)=-18
So the range of the function in [0,1] is [- 18, - 12]

Let a and B be the intersection points of the straight line 3x + 4Y + 2 = 0 and the circle x ^ 2 + y ^ 2 + 4Y = 0, then the equation of the vertical bisector of ab,

x²+(y+2)²=4
Center (0, - 2)
The vertical bisector of string AB passes through the center of the circle
3x + 4Y + 2 = 0, the slope is - 3 / 4
So the vertical slope is - 4 / 3
So y + 2 = - 4 / 3 * (x-0)
That is 4x + 3Y + 6 = 0

Given the quadratic function f (x-4) = f (2-x), how to find the axis of symmetry

[（x-4)+(2-x)]/2=-1
So the axis of symmetry is x = - 1