Question

Let f(x)=arctan(√4x−1). Find f′(x)

Answer 1

do you mean \[\arctan(\sqrt{4x-1})\]
or \[\arctan (\sqrt{4x}-1)\]

Answer 2

The first one.

Answer 3

simplify 1/(1+4x+1) * 1/2* 1/sqrt(1+4x) * 4

Answer 4

\[d/du \tan^{-1} u=u'/(1+u^2)\]

Answer 5

@experimentX is right just replace 1+4x with 4x-1\[{1\over(4x-1+1)} * \frac12* {1 \over \sqrt{4x-1}}* 4\]

Answer 6

If you do a u-substitution and make \[u=\sqrt{4x-1}\], what I wrote will make more sense.

Answer 7

Oo ... right right ... must be sleeptyping

Answer 8

@PaxPolaris How did you write the fraction?

Answer 9

{a \over b}
or
\frac {a} {b}

Answer 10

right click --> Show math as --> Tex commands to see how it's written