SOLUTION: f(x)=5x^3+5x^2-x+C f(3)=1 Find C

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Question 316382: f(x)=5x^3+5x^2-x+C
f(3)=1
Find C
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Since f(3)=1, this means that if we plug in x=3, we'll get f(x)=1.


f%28x%29=5x%5E3%2B5x%5E2-x%2BC Start with the given function.


f%283%29=5%283%29%5E3%2B5%283%29%5E2-3%2BC Plug in x=3


1=5%283%29%5E3%2B5%283%29%5E2-3%2BC Plug in f%283%29=1. Our goal is to now solve for C.


1=5%2827%29%2B5%283%29%5E2-3%2BC Cube 3 to get 27


1=5%2827%29%2B5%289%29-3%2BC Square 3 to get 9


1=135%2B45-3%2BC Multiply


1=177%2BC Combine like terms.


1-177=C Subtract 177 from both sides.


-176=C Combine like terms.


So the value of C is C=-176 making the function f%28x%29=5x%5E3%2B5x%5E2-x-176