Question

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

Answer 1

Answer:

c = -4

Step-by-step 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

Answer 2

• Put 2in place of x

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

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

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

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

$\\ \tt\hookrightarrow 14+c=10$

$\\ \tt\hookrightarrow c=-4$