Given the function f (x) = X3 + bx2 + CX + 2, get the extremum - 1, get the value of B and C x=1

Given the function f (x) = X3 + bx2 + CX + 2, get the extremum - 1, get the value of B and C x=1

If it is at 2, f (2) = 8 + 2B + 2C = - 1
F′（X）=3X^2+C F′（2）=12+c=0 ②
The solution of simultaneous equations is C = - 12, B = 15 / 2

Let f (x) = X3 + bx2 + CX obtain the extremum at point (1,0) (I) find the value of B and C; (II) find the monotone interval and extremum of G (x)

If f (x) = X3 + bx2 + CX obtains the extreme value at the point (1,0), f '(x) = 3x & # 178; + 2bx + C f' (1) = 3 + 2B + C = 0f (1) = 1 + B + C = 0, then B = - 2 C = 1, so f (x) = x & # 179; - 2x & # 178; + XF '(x) = 3x & # 178; - 4x + 1 = (x-1) (3x-1) > 0, then x > 1 or X

Given that the image of function f (x) = x + B is tangent to the image of function g (x) = x ^ 2 + 3x + 2, f (x) = f (x) g (x)
g'(x)=2x+3
Tangent slope = 1
So G '(x) = 1
x=-1
g(-1)=0
So tangent (- 1,0), he's on tangent
So f (- 1) = 0
b=1
How can I find the slope here = 1

F (x) derivative = 1, that is, its tangent slope = 1; two images are tangent, so the slope is equal, that is, G (x) derivative = 1, so the tangent point can be obtained····
I haven't done Math for a long time

There is a biggest square in the big circle. There is a biggest circle (small circle) in the square. The circumference of the big circle is 75.36 cm. Find the area of the small circle

The diameter of the big circle can be calculated from the perimeter (with the perimeter formula), and then the side length of the square can be calculated from the diameter of the big circle (Pythagorean). If the diameter of the largest small circle is the side length of the square, the radius of the small circle can be calculated, and then the area of the small circle can be obtained
The diameter of the big circle: 75.36/π, that is, the hypotenuse of a right triangle with a square divided into two is 75.36/π
∵is RT △ a
∴a=b≈16
∵ diameter of small circle = side length of square = 16
The radius is 8
S small circle = 64 π

If a and B are rational numbers, a + B = A-B; try to find the value of ab

|a+b|=a-b
When a > b
a+b=a-b
2b=0
b=0
When AB or a

Mathematics application problem, kind-hearted person helps me! Beg ~ urgent~
(1) Dongdong went to the sporting goods store to buy table tennis. He said, "it's 8.9 yuan less to buy 10, and 1.6 yuan less to buy five. How much does Dongdong have?
(2) Huanhuan's online fee in June is 180 yuan. If the hourly online fee is 2.40 yuan, how long does Huanhuan's family spend on the Internet every day?
(3) Mother bought 3 kg radish and 1 kg cabbage to share 10 yuan. Known cabbage 2.2 yuan per kg. Radish how much yuan per kg?
(4) There are 23 boys in class 5 (2) with an average height of 1.48 meters and 22 girls with an average height of 1.45 meters

1.(8.9+1.6)/(10-5)=2.1
2.1*5+1.6=12.1
2.180/2.4/30=2.5
3.(10-2.2*1)/3=2.6
4.(23*1.48+22*1.45)/(23+22)=1.46533333333

One side of the square is increased by 2cm, and the other side is decreased by 3cm. The area of the rectangle is 14 square centimeters less than that of the square. Find the side length of the square line

x^2-(2+x)*(x-3)=14
x+6=14
x=8

The orbit of a planet and the earth around the sun can be regarded as a circle. Every n years, the planet will move to the extension line of the sun earth line, and the ratio of the radius of revolution of the planet and the earth is (n / (n-1)) ^ (2 / 3)
Why n / n-1

According to Kepler's third law, R & # 179 / R & # 179; = T & # 178 / T & # 178;
The earth has a small period and rotates fast. It needs to rotate one more circle to be in line with the planet. But the total time is equal. So there is nt = (n-1) t
T/t=n/(n-1)
So R / r = ³ √ [n / (n-1)] ²

Second year physics people's Education Edition Volume I electrical map title?
The more, the better!

When you see a circuit diagram, you first identify whether it is series or parallel
If it is in series, for example, a circuit is from the positive pole to the switch s to the consumer L1 to the consumer L2 to the negative pole, then we might as well write the current direction on the draft paper first:
+ → S→L1→L2→ -
Then, according to this, you can connect the real pictures in turn
If it is in parallel, let's first make clear how many paths there are from the positive pole to the negative pole. For example, in a parallel circuit, the main path is from the positive pole to the switch s, the first branch is from the switch S1 to the consumer L1, and the second branch is from the switch S2 to the consumer L2. Then we write the current directions of the two branches respectively:
+ →S→S1→L1→ -
+ →S→S2→L2→ -
Then find out the same parts, then these same parts are a road, and then start to bifurcate in different parts, so as to connect the real pictures, which is very effective,

Given that the length of the rectangle is √ 10cm and the width is √ 6cm, the area of the rectangle is?

The area of this rectangle is
=Length × width
=√10×√6
=√60
=2√15.