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41 votes
If f(x)= 2x^2+1, what is f(x) when x=3

User MrPlow
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2 Answers

6 votes
6 votes

The answer is:

f(3) = 19

Work/explanation:

To evaluate the function, I plug in 3 for "x" :


\rm{f(x)=2x^2+1}


\rm{f(3)=2(3)^2+1}

Then, I square 3:


\rm{f(3)=2*9+1}

Take caution here; we do not add 9 + 1, we multiply 2 times 9 first, and only then, we add 1.


\rm{f(3)=18+1}


\rm{f(3)=19}

Hence, the answer is f(3) = 19.

User RD Ward
by
3.0k points
18 votes
18 votes

Hey there!

f(x) = 2x^2 + 1

y = 2x^2 + 1

y = 2(3)^2 + 1

3^2

= 3 * 3

= 9

y = 2(9) + 1

2(9) = 18

y = 18 + 1

y = 19

Answer: y = 19

Good luck on your assignment and enjoy your day!

~Amphitrite1040:)

User Ian Brown
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2.8k points