Question

Graph y=4x+ 6 to test which solution is correct. Explain your thinking. A. x=7, if 4x + 6 = 29 B. x = 9, if 4x + 6 = 42.​

Answer 1

Answer:

Correct option is

B

two

Since(x)=1−(1−x

2

)=x(2−x), we have f(f(x))=x(2−x)(2−x(2−x)).

Hence x=0 is one of the solution for f(f(x))=x.

Now if x



=0, then f(f(x))=x can be written as

(2−x)(2−x(2−x))=1

Simplifying we get, x

3

−4x

2

+6x−3=0.

Note that x=1 is solution of this equation and the other two roots are complex numbers.

Hence the for the given function, f(f(x))=x has two real roots for x≤1