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If f(x)=2x^3-x+c and f(2)=10 then what's the value of c?

User DimaTX
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2 Answers

7 votes
  • Put 2in place of x


\\ \tt\hookrightarrow 2x^3-x+c=10


\\ \tt\hookrightarrow 2(2)^3-2+c=10


\\ \tt\hookrightarrow 2(8)-2+c=10


\\ \tt\hookrightarrow 16-2+c=10


\\ \tt\hookrightarrow 14+c=10


\\ \tt\hookrightarrow c=-4

User Ben Alex
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3.1k points
8 votes

Answer:

c = -4

Explanation:

If f(x) = 2x^3 - x + c and f(2) = 10, plug in 2 for the x values in the function and make the function output 10.

10 = 2(2^3) - 2 + c Now, we only have to deal with one variable, that is c.

10 = 2(8) - 2 + c

10 = 16 - 2 + c

10 = 14 + c

-4 = c After simplifying, we get that c is -4.

To check this, plug in 2 for x, and -4 for c in the function. If the function produces 10 as the result, the halleluja!

f(2) = 2(2^3) - 2 - 4

f(2) = 2(8) - 2 - 4

f(2) = 16 - 2 - 4

f(2) = 10

User Skink
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