Yi Zhi, x≠0.
When both sides of the original equation are divided by x, (m- 1)+x+( 1/x)=0.
∴ 1-m=x+( 1/x).
The constructor f (x) = x+( 1/x). (0 < x ≤ 2)。
According to the monotonicity of "tick function", there are
x+( 1/x)≥2。
∴ 1-m≥2.
m≤- 1。
2
According to the topic:
4a? +(b? + 1)=5.
∴√(b? + 1)=√(5-4a? ) and 0 < a < 1.
∴y=a√( 1+b? )
=a√(5-4a? )
=√[a? (5-4a? )]
=√{(25/ 16)-4[a? -(5/8)]? }≦5/4.
The equal sign can only be obtained when a=(√ 10)/4.
∴ymax=5/4.
3∶x > 1。
∴ x- 1 > 0, according to the basic inequality:
(x- 1)+[ 1/(x- 1)]≥2。 The equal sign can only be obtained when x=2.
∴x+[ 1/(x- 1)]≧3.
∴min=3.
four
5 You can set the general term an = a 1× q (n- 1).
a3=a 1×q? ,a5=a 1×q^4,a6=a 1×q^5.
∴ From 2a5=a3+a6, we can get:
2q? = 1+q? .
q? -2q? + 1=0.
(q? -q? )-(q? - 1)=0
(q- 1)(q? -q- 1)=0。
∴q? =q+ 1。 Solution: q=( 1+√5)/2.
Original formula =(q? +q^4)/(q^3+q^5)
=( 1+q? )/(q+q? )
= 1/q。
=2/( 1+√5)
=(√5- 1)/2.