Question 9: How many extremes does the function \(y = {x^4} + {x^2} + 1\) have?

We have \(y’ = 4{x^3} + 2x = 4x\left( {2{x^2} + 1} \right) = 0 \Leftrightarrow x = 0\)

And y’ changes sign when going through x = 0, so the function has only 1 extreme

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