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How much square is 30 cm multiplied by 47 cm
Ren Lijun 555,
30cm × 47cm = 1410 (cm2)
A mathematical problem of calculating shadow length in sunlight
In the sun, when a big ball is placed on a horizontal plane, the shadow of the ball reaches 10 meters away from the contact point between the ball and the ground. At the same time, if the shadow of a bamboo pole with a length of 1 meter and one end touching the ground and perpendicular to the ground is 2 meters long, the radius of the ball is equal to
As shown in the figure, SQR (5) stands for root 5
Y=2R/Sqr(5)
X=R/Sqr(5)
yes
2*[R*(1+2/Sqr(5))]+R/Sqr(5)=10
The solution is r = 10 * (SQR (5) - 2)
Here is the picture
How much is five percent
0.05
Given that the solution of equation 3x-ax = 2 is - 1, find the square of (1-A)
Substitute x = - 1 into the equation
-3+a=2
a=5
Square of 1-A = (1-5) = 16
What is 35 degrees 42 seconds
35.7 degrees
Solution equation: 4x-1.25 * 8 = 3.4
4x-1.25*8=3.4
4x-10=3.4
4x=10+3.4
4x=13.4
x=13.4÷4
x=3.35
If you don't understand this question, you can ask,
What's the simple way to multiply 39 out of 40 by 27?
1x27－39/40
It is known that a, B and C are the three internal angles of △ ABC and satisfy 2sinb = Sina + sinc. Let B have the maximum value of B0. (I) find the size of B0; (II) find the value of Cosa COSC when B = 3b04
From the cosine theorem, CoSb = A2 + C2 − b22ac = A2 + C2 − (a + C2) 22ac = 3 (A2 + C2) − 2ac2ac ≥ 6ac − 2ac8ac = 12. (4 points) because y = cosx monotonically decreases on (0, π), the maximum value of B is B0 = π 3. (6 points) (II) let Cosa COSC = x, and (8 points) from (I) and the proposition Sina + sinc = 2 So, 2-2cos (a + C) = x2 + 2. (10 points) and because a + C = π - B = 3 π 4, x = ± 42, that is, Cosa COSC = ± 42. (14 points)
What is the difference between 1235 * 6788 and 1234 * 6789
(1234+1)*(6789-1)-1234*6789=(1234*6789-1234*6789)-1234+6789-1=5554
Given that the vertex of the parabola y = x2-8x + C is on the X axis, then C is equal to ()
A. 4B. 8C. -4D. 16
According to the meaning of the question, we get 4C − (− 8) 24 × 1 = 0 and C = 16
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