The functions f and g are defined above. If f (a) = g (a), what is the value of a

Answer: (B) –1
Explanation
We are given functions f(x) and g(x), and we are aked to fins a when f(a) = g(a). Therefore, we have to set the equations equal to each other. Additionally, we have to replace x with a:
[tex]f(a)=g(a)[/tex][tex]a(a+1)=(a^2-1)[/tex]First, we have to multiply the a outside the parenthesis times the terms inside the parenthesis:
[tex]a^2+a=a^2-1[/tex]Then, we have to get all the similar terms to each side of the equation and simplify:
[tex]a^2-a^2+a=-1[/tex][tex]a=-1[/tex]