Under the microscope, the shape of a kind of cell in human body is approximately round. Its diameter is about 1.6 × 10 - 6 cubic meters π is 3.14

Under the microscope, the shape of a kind of cell in human body is approximately round. Its diameter is about 1.6 × 10 - 6 cubic meters π is 3.14

3.14 times 6.4 times 10 to the negative thirteenth power

How to do simple calculation 4800 / 16 / 30

4800/16/30
=4800/(16×30)
=4800/480
=10

All the formulas in primary school mathematics published by Jiangsu Education Press

The basic relation of trigonometric functions with the same angle reciprocal relation: quotient relation: square relation: Tan α · cot α = 1 sin α · CSC α = 1 cos α · sec α = 1 sin α / cos α = Tan α = sec α / CSC α cos α / sin α = cot α = CSC α / sec α sin 2 α + cos 2 α = 1

Who can divide 52 / 91

Maximum common factor: 13
About 52 / 91 = 13 * 4 / 13 * 7 = 3 / 7

The formation of solar and lunar eclipses

Solar and lunar eclipses are directly related to the position of the sun, the earth and the moon. Because the earth and the moon are opaque planets, they will not emit light. The moon we see is actually the sunlight reflected by the moon. If you have a chance to see our earth in space, you will find that it is more beautiful than the moon

There is a book with 85 pages. Xiao Jun has read page a every day for four days______ Page: when a = 10, there's more left______ I didn't read the page

According to the stem analysis, Xiaojun has read page 4a, when a = 10, there are still 85-4a, = 85-4 × 10, = 85-40, = 45 (pages). A: he has read page 4a, when a = 10, there are still 45 pages left. So the answer is: 4a; 45

Sixth grade math problems, a little difficult, sure to come
1. The outer diameter of a bicycle tire is about 60 cm. How many minutes does it take to turn 240 times per minute and cross a section of 9420 meters?
2. We all know that the monkey king is not afraid of heaven and earth, but the monkey king also has a fear, that is, he is afraid of the mantra chanted by his master Tang monk. Since the monkey king is put on, he has lost his freedom. If the mantra on the monkey king's forehead is just attached to his forehead, and the diameter of the forehead is 16 cm, every mantra chanted by Tang monk will shorten the original length by 100% How deep will the Tang Monk's two sentences of mantra and the tight mantra shrink into Wukong's scalp?

1. The outer diameter of bicycle tire is about 60cm, perimeter = 3.14 * 60 = 188.4cm = 1.88m,
9420 / (240 * 1.88) = 20.88 (min)
2.16 / 2 * 1% + 16 / 2 * (1-1%) * 1% = 0.1592 (CM)

Help me to do the question 9 △ 0.125 is equal to how much, to simple calculation
Don't give me a fraction

9÷0.125
=(10-1)÷0.125
=10÷0.125-1÷0.125
=80-8
=72

Given the quadratic function f (x), when x = 12, there is a maximum value of 25, and the sum of two cubes of F (x) = 0 is 19, the analytic expression of F (x) is obtained

Let f (x) = a (X-12) 2 + 25 = AX2 ax + A4 + 25, let two of F (x) = 0 be m and N, then the sum of M + n = 1, Mn = 14 + 25A, the sum of two cubes of F (x) = 0 is 19, ｜ m3 + N3 = (M + n) (M2 + N2 Mn) = (M + n) [(M + n) 2-3mn] = 1 × [1-3 (14 + 25a)] = 19, and the solution is a = - 4, ｜ f (x) = - 4 (x − 12) 2 + 25

The original unit price of a garment is 300 yuan. After two consecutive price increases of a%, the selling price is 363 yuan. How much is a

300*(1+a%)(1+a%)=363
(1+a%)^2=1.21
1+a%=1.1
a%=0.1
a%=10%
a=10