Question

State the maximum and mini mum value of
f(x)= x^2+9

Answer 1

`a>0 \Rightarrow \hbox{no maximum}`


`y_(min)=(-b^2+4ac)/(4a)\\y_(min)=(-0^2+4\cdot1\cdot9)/(4\cdot1)\\ y_(min)=9`

Answer 2

`f(x)= x^2+9\\\\for\ each\ x\in R\\\\x^2 \geq 0\ \ \ \Rightarrow\ \ \ x^2+9 \geq 9\ \ \ \Rightarrow\ \ \ f(x) \geq 9\\\\y_(min)=9\\ y_(max)\ \ \ \rightarrow\ \ \ not\ exist`