As shown in the figure, it is known that AC = CE, ∠ 1 = 2 = 3 (1) Explain the reason of ∠ B = D; (2) explain the reason of AB = De

As shown in the figure, it is known that AC = CE, ∠ 1 = 2 = 3 (1) Explain the reason of ∠ B = D; (2) explain the reason of AB = De

(1) ∵∠ 1 = ∠ 2, ∠ AFD = ∠ BFC, ∩ AFD ∽ CFB, ∩ B = ∠ D; (2) there are (1) known: ∩ B = ∠ D, ∩ 2 = ∠ 3, ∩ DCE = ∠ ACB, ≌ ABC ≌ EDC, ≌ AB = de (the corresponding sides of congruent triangles are equal)

If a is known to be a non-zero constant and X belongs to R, f (x + a) = 1 + F (x) / 1-f (x) (f (x) is not equal to 0), try to judge whether f (x) is a periodic function and prove that

F (x) = 1 + F (x-a) / 1-f (x-a), f (x) = 1 + F (x-a) / 1-f (x-a), f (x) = 1 + F (x-a) / 1-f (x-a), f (x) obtained above is taken into the known condition given in the question, f (x + a) f (x-a) = - 1 is sorted, and X is replaced by X + A, then f ((x + a) + a) f ((x + a) - a) = f (x + 2a) f (x) = - 1

Given the function f (x) = a ^ x (a > 0. A is not equal to 1) and f (2) = 4, find the analytic expression of F (x), let the constant B satisfy f (b)

f(2)=a²=4
a=2
So f (x) = 2 ^ X
Because a > 1
So it's an increasing function
f(b)