Plugin Problem

[Jason76]

\(\displaystyle f(x) = x^{4} - 32x^{2} + 1\)

\(\displaystyle f(\dfrac{16}{3}) =( \dfrac{16}{3})^{4} - 32(\dfrac{16}{3})^{2} + 1 = -\dfrac{8111}{81}\) - This is wrong on the computer.

 

[stapel]

\(\displaystyle f(x) = x^{4} - 32x^{2} + 1\)

\(\displaystyle f(\dfrac{16}{3}) =( \dfrac{16}{3})^{4} - 32(\dfrac{16}{3})^{2} + 1 = -\dfrac{8111}{81}\)

What were the instructions? Are you supposed to evaluate f(x) at t = 16/3, or something else? If evaluating, is there any particular method you are supposed to be using?

I haven't checked your arithmetic. What, precisely, are you asking? What do you need?

 

[Jason76]

Answer was wrong on computer homework. But then again I think, in this case, I was supposed to use \(\displaystyle \pm \sqrt{\dfrac{16}{3}}\)

\(\displaystyle f( \sqrt{\dfrac{16}{3}}) =( \sqrt{\dfrac{16}{3}})^{4} - 32( \sqrt{\dfrac{16}{3}})^{2} + 1 =?\)

And

\(\displaystyle f(- \sqrt{\dfrac{16}{3}}) =( -\sqrt{\dfrac{16}{3}})^{4} - 32( -\sqrt{\dfrac{16}{3}})^{2} + 1 =?\)

 

[JeffM]

Answer was wrong on computer homework. But then again I think, in this case, I was supposed to use \(\displaystyle \pm \sqrt{\dfrac{16}{3}}\)

\(\displaystyle f( \sqrt{\dfrac{16}{3}}) =( \sqrt{\dfrac{16}{3}})^{4} - 32( \sqrt{\dfrac{16}{3}})^{2} + 1 =?\)

And

\(\displaystyle f(- \sqrt{\dfrac{16}{3}}) =( -\sqrt{\dfrac{16}{3}})^{4} - 32( -\sqrt{\dfrac{16}{3}})^{2} + 1 =?\)

You have not shown us your work. So how in the world can we tell you where you went wrong (if you did)?