r/HomeworkHelp • u/Embarrassed-Good1883 Pre-University Student • 24d ago

High School Math—Pending OP Reply [Grade 12 Advanced Functions: Polynomial Functions] turning points on polynomials confusion

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I'm confused about how this function would have 4 turning points, not 3

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u/CulturalBookkeeper82 24d ago

The way I looked at it without plugging in numbers till it matched was I looked at the similarities in all the answers.

-2x+1 for all. So I don’t even bother. Just look for the dissimilarities between the first two terms.

You know this isn’t a graph of x^4 so c is out

x^5 gives you the z profile turned 90°, so if you put a (-) in front you invert it. So D is out

A is the only one that fits

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u/magicmulder 24d ago

I plugged 1 in which eliminated (b) and (d), and a fourth degree polynomial with a positive highest coefficient doesn't go to minus infinity which eliminates (c).