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As shown in the figure, we know that the side length of equilateral triangle ABC is 3, M is a point on AC, passing through point m, make me parallel AB, intersect BC at point E, make MF ⊥ AB at point F, let AF = x, the median line length of trapezoidal emfb is y, find out the function analytic formula of Y and X, and write out the value range of X
In the right angle △ AFM, ∵ ∠ a = 60 °,
∴∠AMF=30°,
∵AF=x,∴AM=2x,
∴CM=3－2x,
And me ‖ AB,
Easy to prove: △ CEM is equilateral,
∴ME=3－2x,BF=3－x,
The median line length of trapezoidal emfb
y=½﹙ME＋BF﹚=½×﹙3－2x＋3－x﹚=3－﹙3／2﹚x,
Obviously 0 ＜ x ＜ 3 / 2
As shown in the figure, in rectangular ABCD, the bisector of ∠ ABC intersects the diagonal AC at points m, me ⊥ AB, MF ⊥ BC, and the perpendicular feet are e and f respectively, so as to judge the shape of quadrilateral EBFM
Shape: Square
∵ rectangle ABCD
∴∠ABC=90°
∵MF⊥BC,ME⊥AB
∴∠BFM=∠MEB=90°
∵∠ABC=∠BFM=∠MEB=90°
The quadrilateral BFME is a rectangle
∵ BM bisection ∠ ABC
∴∠EBM=∠EMB
The EBM is an isosceles triangle
∴BE=EM
The quadrilateral EBFM is a square
As shown in the figure, in the triangle ABC, point D is on AB, CE bisector angle ACD, EF is parallel to CD, when BF is perpendicular to CE, BC = B
Reasons for
It is proved that if the vertical line of AB crosses point a, and the extension line of BF intersects m.ac = BC, CD ⊥ AB, then ad = BD; if am is parallel to CD, then DH / am = BD / BA = 1 / 2, DH = am / 2
Let a triangle B = 3A minus 2B, X triangle (4, triangle 1) = 7, find X
Urgent, please explain the reason
This is a problem of defining symbols, that is, a Δ B = 3a-2b
xΔ(4Δ1)=xΔ(3*4-2*1)=xΔ10=3x-2*10=7
Solve the equation and get x = 9
How to draw the image of F (x) = x + 1 / x
The characteristic is roughly the same as that of the inverse scale function. If you draw a graph, you can see it. F (x) = x + 1 / X-2 + 2 = (root X-1 / root x) square + 2. Only when x > 0 can you find the minimum value. When x = 1 / x, that is, x = 1, the minimum value of F (x) is 2, when x = 1 / x, the minimum value of F (x) is 2
How to draw an image with F (x) = 2|x-1| - x + 1
A:
f(x)=2|x-1|-x+1
When X & lt; = 1: F (x) = 2 (1-x) - x + 1 = - 3x + 3
When X & gt; = 1: F (x) = 2 (x-1) - x + 1 = X-1
What is axonometric drawing? How to draw axonometric drawing?
Axonometric drawing is similar to three-dimensional drawing! Compared with two-dimensional drawing, it is more intuitive and clear
CAD can draw axonometric drawing. It is suggested that we should first take a look at the basic knowledge of mechanical drawing
Drawing method of isometric drawing
Length is equal to width
How to judge the visibility of isometric drawing
This is not a very good question to answer. The premise is that you need to know how to draw a positive isometric map. Generally speaking, you start from the line near the far point and draw "near first and then far", and the following coverage is drawn first. In fact, it is more about your own thinking and judgment, and there are not many skills in drawing
On the drawing method of positive equal side and oblique two survey
If a circular hole is pierced in the middle of an object, is it an ellipse drawn by the equal side drawing method? What kind of ellipse is it drawn by the oblique two survey method? Circle or ellipse?
Equal sides draw a circle, and oblique sides draw an ellipse
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