If f(x) =2x^3 + Ax^2 + 4x - 5 and f(2) = 5, what is the value of A? I keep getting = -31\2 but the correct answer is -7/2 how do I get that? :| thank you
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Originally Posted by cokeclassic If f(x) =2x^3 + Ax^2 + 4x - 5 and f(2) = 5, what is the value of A? I keep getting = -31\2 but the correct answer is -7/2 how do I get that? :| thank you $\displaystyle f(2) = 5$ means $\displaystyle 2(2)^3 + A(2)^2 + 4(2) - 5 = 5$ $\displaystyle \Rightarrow 16 + 4A + 8 - 5 = 5$ from here, simple arithmetic will get you the right answer (-7/2). want to try?
Oh opps... I multiplied 2 x 2 first Thank you
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