Let a = {(x, y) │ x = a, y ∈ r}, B = {(x, y) │ x ^ 2 / 4 + y ^ 2 = 1}, a ∩ B = &;, then the value range of real number a is

Let a = {(x, y) │ x = a, y ∈ r}, B = {(x, y) │ x ^ 2 / 4 + y ^ 2 = 1}, a ∩ B = &;, then the value range of real number a is

According to B, we know that - 2

Given that the function y = f (x) is an increasing function on R + and f (M & # 178;) > F (- M), then the value range of real number m is?

The domain is r+
So M & # 178; > 0
-m>0
So M-M
m(m+1)>0
m0
To sum up
m

If the function y = f (x) increases monotonically on R and f (M & # 178;) > F (- M), then the value range of real number m is

∵ function y = f (x) increases monotonically on R
And f (M2) > F (- M)
∴m2>-m
∴m2+m>0
∴m(m+1)>0
｜ m > 0 or M0 or M

A = {x | x ^ 2 + 4x = 0}, B = {x | x ^ 2 + 2 (a + 1) x + A ^ 2-1 = 0}, and a ∩ B = B, find the value range of real number a

X ^ 2 + 4x = 0x (x + 4) = 0, that is, x = 0 or - 4, substitute x = 0 into x ^ 2 + 2 (a + 1) x + A ^ 2-1 = 0, a ^ 2-1 = 0, that is, a = 1 or - 1, substitute a = 1 into x ^ 2 + 2 (a + 1) x + A ^ 2-1 = 0, get x ^ 2 + 4x = 0, x = 0 or - 4, so a = 1 satisfies the problem, substitute a = - 1 into x ^ 2 + 2 (a + 1) x + A ^ 2-1 = 0, get x ^ 2 = 0