If f (X & # 178; + 1) = x & # 8308; + X & # 178; + 1 = f (x)

If f (X & # 178; + 1) = x & # 8308; + X & # 178; + 1 = f (x)

This kind of problem is the simplification problem, which is to simplify the expression on the right into brackets
f(x²+1)=x⁴+x²+1=（x²+1）²-(x²+1)+1
So f (x) = x & # 178; - x + 1

F (x) = x & # 8308; - 2x & # 178; + 3 to judge the parity of functions

f(x)=x⁴ - 2x² +3
f(-x)=x⁴ - 2x² +3
f(x)=f(-x)
It's an even function

Known: x + 1 / x = 4, evaluation: X & # 178 / / X & # 8308; + X & # 178; + 1

=x^2+1/x^2+1=x^2+1/x^2-2+2+1=(x+1/x)^2-1=15

Solving equation with square root
(1)x^2=0.64
(2)3a^2=4
Just two questions!
Do me a little favor~
First floor There is a process
forget it. I'll do it myself
Give it to you

...
1] Plus or minus 0.8
2] Plus or minus two thirds [square on 3A] plus or minus four thirds root sign three [square on a]