I am trying to figure this section out for myself before the teacher lectures on it so if some can explain this one to me would be great
g(f(-3)) f(x)=\[\sqrt[3]{x+1}\] \[g(x)=4x^{2}-x\]
Well first sub in the value of -3 into f(x) and see what you get
can you first find f(-3) ? just put x=-3 in f(x)
\[\sqrt[3]{-3+1}=\sqrt[3]{-2}\] ?
Yeah that look about right
Then you put that into the place of x in g(x), and solve the equation
so \[4\sqrt[3]{-2}^{2}-\sqrt[3]{-2}\]
Yeah, although that looks really messy, but it should be the right answer
the answer in the book says its \[4\sqrt[3]{4}+\sqrt[3]{2}\]
Yes they are the same form,\[\sqrt[3]{-2}^{2}=\sqrt[3]{4}\] since you can drop the square in
ah yes ok get it
Do you get the second part also?
the - and - signs = + ?
Yes, since the minus sign is technically -1, you can bring that inside the square root and multiply it with -2, where negative and negative make positive
thanks :)
No probs :D
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