Maximum & Minimum value.

The greatest and least value of the function f(x)=x^42x^2+5 on [2,2].
Options:
 13 and 4
 9 and 2
 11 and 3
 None of these


@shreyasvarma I didnt understand why after taking x^2=t with should be f(√t)

@anujpatil
New function is F(t) and not F(√t)

@shreyasvarma can you explain in detail actually i didn't get why we can't directly differentiate and get the answer and why is there a need for substitution.
And how to change the limits.And can you explain the sum in detail.

@anujpatil
Substitution is just for the ease of solving. As we substitute x²=t, as the domain of f(x) is [2,2], the domain of new function f(√t) will be 0,4 but the function remains the same. And therefore max and min values are same

@anujpatil
My mistake. New function is f(√t) but it is same as f(x)

@shreyasvarma Can you show without substituion.

@anujpatil
Method of substitution was lot more simpler as you can see.

Thank You @shreyasvarma !