A simple method is used to calculate: 2004 × 20052005-2005 × 20042004

A simple method is used to calculate: 2004 × 20052005-2005 × 20042004

2004×20052005-2005×20042004=2004×2005×10001-2005×2004×10001=10001×（2004×2005-2005×2004）=0．

As shown in the figure, ⊙ P and ⊙ o intersect at two points a and B, ⊙ P passes through the center O, and point C is any point of AB on the superior arc of ⊙ P (not coincident with points a and b), connecting AB, AC, BC and OC. (1) point out an angle equal to ∠ ACO in the figure; (2) when point C is at what position on ⊙ P, is the straight line CA tangent to ⊙ o? Please explain the reason; (3) when ∠ ACB = 60 °, what is the size relationship between the radius of two circles? Please state your reasons

(1) In ⊙ o, ⊙ OA = ob, ⊙ OA = ob, ⊙ ACO = ⊙ BCO; (2) connect OP and extend the intersection with ⊙ P at point D. if point C is at point D, the straight line CA is tangent to ⊙ O. reason: connect AD and OA, then ⊙ Dao = 90 °, OA ⊥ Da ⊙ Da is tangent to ⊙ o, that is, when point C is at point D, the straight line CA is tangent to ⊙ O. (3) when ⊙ ACB = 60 °, the radii of two circles are equal Make the diameter OD, connect BD, ad, OA, ∵ ∠ ADB = ∠ ACB = 60 ° Po, divide AB, Ao = Bo, ∵ ∠ ADO = ∠ BDO, ∵ ADO = 30 °, ∵ od is the diameter, ∵ Dao = 90 °, ∵ OA = 12od, ∵ OA = Po, when ∠ ACB = 60 ° the radii of the two circles are equal

If a three digit number is divided by 58, the quotient A is more than B (both a and B are natural numbers), and the maximum value of a + B is______ ．

According to the meaning of the question, the maximum remainder is 57, the maximum quotient A is: (999-57) △ 58 ≈ 16, the maximum value of a + B is: 16 + 57 = 73

As shown in the figure, in △ Abe, ab = AE, ad = AC, ∠ bad = ∠ EAC, BC and de intersect at point o

In △ ABC and △ AED, in △ ABC and △ AED, ab = AE in △ ABC and △ AED, ab = AE, in △ ABC and △ AED, ab = AE, in △ ABC and △ AED, ab = AE. In △ ABC and △ AED, ab = AE, ab = AE, in △ ABC = eadac = ad, and △ ABC △ AED (eaddac) (as) in @ (2) by (2) knowing (1) from (1) from (1) from (1) knowing (1) knowing 2

10 / 13 / 2 and 19 / 22-1.4 × 11 / 13 + 7 + 22 / 63% =?

The original formula = (10 / 13) / (63 / 22) - (7 / 5) * (11 / 13) + 7 + (22 / 63) * (1 / 5) = (10 / 13) * (22 / 63) + (22 / 63) * (1 / 5) - (77 / 65) + 7 = (22 / 63) * (10 / 13 + 1 / 5) - (77 / 65) + 7 = (22 / 63) * (63 / 65) - (77 / 65) + 7 = (22 / 65) - (77 / 65) + 7 = - 11 / 13 + 91 / 13 = 80 / 13

How to transform symbolic matrix into numerical matrix

For example: > > A = [1 / 3, sqrt (2); 2 / 3, sqrt (5)] a = 0.3333 1.41420.6667 2.2361 > > b = sym (a)% a is a numerical matrix, first convert it into a symbolic matrix B = [1 / 3, sqrt (2)] [2 / 3, sqrt (5)] > > C = double (b) C

7.09 divided by 0.52 is about how much

=13.634615

Sample type: Ser / PI in biochemical analyzer. What does this Ser / PI mean?

Ser is the abbreviation of serum and PL is the abbreviation of plasma

How much is 10 out of 9 - (11 out of 9 + 1 out of 9)?

(10/9)-(1/(9/11)) = (10/9)-(11/9)=-1/9

When limx tends to 0, find: (e ^ tanx-e ^ x) / (x-sinx),

When limx tends to 0, (e ^ tanx-e ^ x) / (x-sinx) = LIM (x - > 0) e ^ x (e ^ (tanx-x) - 1) / (x-sinx) = LIM (x - > 0) (e ^ (tanx-x) - 1) / (x-sinx) = Lim (x - > 0) (tanx-x) / (x-sinx) = LIM (x - > 0) (SEC & # 178; x-1) / (1-cosx) = LIM (x - > 0) (Tan & # 178; x) / (1 -