Given that C is a constant, the opposite number of a root of the equation x & sup2; - 3x + C = 0 about X is a root of the equation x & sup2; + 3x-c = 0 It's worth it. Thank you Find the root of the equation x & sup2; - 3x + C = 0 and the value of C.

Given that C is a constant, the opposite number of a root of the equation x & sup2; - 3x + C = 0 about X is a root of the equation x & sup2; + 3x-c = 0 It's worth it. Thank you Find the root of the equation x & sup2; - 3x + C = 0 and the value of C.

Let the roots be a and - A
Then a & sup2; - 3A + C = 0
a²-3a-c=0
subtract
c=0
x³-3x+c=x²-3x=x(x-3)=0
x=0,x=3

It is known that the water tank is 5 tons, and 1 ton of water is equivalent to the volume of 1 cubic meter of water tank. It is known that the width is 1.4 meters and the length is how many meters

=5 / 1.4/3 ≈ 1.2m

1. How much is the length, width and height of the 2 cubic meter cuboid water tank with cover
There should be a specific process

Let length, width and height be x, y and Z respectively
xyz=2
The surface area is f (x, y, z) = 2XY + 2yz + 2XZ = 2xyz (1 / x + 1 / y + 1 / z) = 4 (1 / x + 1 / y + 1 / z) > = 4 * 2 (XYZ) ^ (2 / 3) = 8 * 4 ^ (1 / 3)
If and only if x = y = Z, then x = y = z = 2 ^ (1 / 3)
Therefore, when the length, width and height are 2 ^ (1 / 3), the material consumption is the most economical