## anonymous 4 years ago f(x) = x^3 + 2x + 6 if A)f^ −1(6) B) f −1(3)

1. anonymous

$f(0)=6\implies f^{-1}(6)=0$

2. myininaya

so we have $\text{ if } f^{-1}(3)=t => f(t)=3$ so this means we need to solve f(t)=3 for t $t^3+2t+6=3$ $t^3+2t+6-3=0$ $t^3+2t+3=0$ We can guess a solution how about t=-1 -1-2+3=0 So yes! t=-3=>f(-3)=3 => $f^{-1}(3)=-3$

3. myininaya

oops t=-1*

4. myininaya

$t=-1=>f(-1)=3=>f^{-1}(3)=-1*$

5. anonymous

perfect thnk you so much ery good explantation as well :)