Find the least value of 4x(squared) + 3 only x is squared
Now for maximum or minimum `dy/dx=0`
The condition is that if `(d^2y)/(dx^2)>0 `
at given value of x it is a point of minimum.
Here we see that `(d^2y)/(dx^2)>0` at `x=0` .
So the minimum value of `y=4x^2+3` is `y=4.0+3`
i.e. `y=3` .