Posted by **Jamie** on Tuesday, January 16, 2007 at 4:55pm.

Let f be a function defined by f(x)= arctan x/2 + arctan x. the value of f'(0) is?

It's 3/2 but I am not very clear on how to obtain the answer. I changed arctan x/2 into dy/dx=(4-2x)/(4sqrt(4+x^2)) but that's as far as I got. Could you please show me how to solve this problem? I would really appreciate it?

Start with this rule:

d/dx (arctan x)

= 1/(1 +x^2)

d/dx (arctan x/2) = (1/2)/[1 + (x/2)^2]

Evaluate them at x = 0 and add them. You will get 3/2.

## Answer this Question

## Related Questions

- precal - The values of x that are solutions to the equation cos^(2)x=sin2x in ...
- Calculus - Note that pi lim arctan(x ) = ---- x -> +oo 2 Now evaluate / pi \ ...
- calculus - Find the exact value of: cos(arctan(2) + arctan(3)) Please explain ...
- Math - Arrange these in order from least to greatest: arctan(-sqrt3), arctan 0, ...
- calc - also: integral of tan^(-1)y dy how is integration of parts used in that? ...
- calculus - h(x)= integral from (1, 1/x) arctan(2t)dt part 1: let U= 1/x and du...
- calculus - h(x)= integral from (1, 1/x) arctan(2t)dt part 1: let U= 1/x and du...
- solving trigonometrical equations - arctan(tan(2pi/3) thanks. arctan(tan(2pi/3...
- calculus - Now we prove Machin's formula using the tangent addition formula: tan...
- Trig - URGENT, Please answer this question: give the value of: Tan(Arctan x+1/x-...

More Related Questions