Posted by **Kate** on Saturday, May 18, 2013 at 9:37am.

Evaluate the expressions:

a) arctan(-sqrt(3))

a) Arctan(-sqrt(3))

So, I know how to find the answers with a calculator, but how do I find it step by step?

- TRIGONOMETRY -
**Steve**, Saturday, May 18, 2013 at 11:47am
by test time you need to know the "standard" angles with easy-to-recall trig functions

0,π/6,π/4,π/3,π/2

If you know those angles and their trig ratios, you will recall that

tan π/3 = √3

Now, recall the bit about principal values of inverse trig functions. You restrict the domain so that the range is one continuous period, containing 0, if possible.

-π/2 <= Arcsin(x) < π/2

0 <= Arccos(x) <= π

-π/2 < Arctan(x) < π/2

...

arctan(-√3) = -π/3 + 2kπ

Arctan(-√3) = -π/3

- TRIGONOMETRY -
**Kate**, Saturday, May 18, 2013 at 1:28pm
Aah, okay! That's easy enough! That makes total sense. Thanks!

## Answer this Question

## Related Questions

- Calculus - 1.Evaluate: (1/(x*sqrt(x^2-4)) I know the answer is -1/2*arctan(2/...
- Math Help please!! - Could someone show me how to solve these problems step by ...
- Calc - Evaluate the integral (3x+4)/[(x^2+4)(3-x)]dx a. (1/2)ln(x^2+4) + ln|3-x...
- Math - Arrange these in order from least to greatest: arctan(-sqrt3), arctan 0, ...
- Trigonometry - I need help with I just can't seem to get anywhere. this is as ...
- calculus - Let f be a function defined by f(x)= arctan x/2 + arctan x. the value...
- Trigonometry - Evaluate the expressions a. arctan(-(sqrt3)) b. Arctan(-(sqrt3)) ...
- precal - The values of x that are solutions to the equation cos^(2)x=sin2x in ...
- PreCalculus - I'm unsure how to even start this problem Solve for x: Arctan( -4/...
- Calc - Can anyone help me find the derivative of these functions? y = x^2x y = x...