Question

Find a formula for the derivatives of the function
g(x)=2x^2-3

Answer 1

So I have\[(2(x+h)^{2}-3)-(2x ^{2}-3)/h\]then multiplying it through I get\[2x ^{2}+2h ^{2}-3-2x ^{2}+3/h\]but they are just canceling out. What am I doing wrong there?

Answer 2

\((2(x+h)^2-3)~~~\longrightarrow~~~2x^2+2h^2-3\) is what you are doing wrong.

\((x+h)^2\neq x^2+h^2\)

Answer 3

Oh goodness. Yep. Makes sense now. Thanks.

Answer 4

No problem