# Solve the equation for exact solutions.

• May 2nd 2013, 04:24 PM
boltage619
Solve the equation for exact solutions.
4pi+4tan^-1 x = pi
• May 2nd 2013, 04:39 PM
MarkFL
Re: Solve the equation for exact solutions.
What have you tried?
• May 2nd 2013, 04:40 PM
boltage619
Re: Solve the equation for exact solutions.
The solution in the book, said that it equals 0 but i'm not sure how to do this problem.
• May 2nd 2013, 06:50 PM
MarkFL
Re: Solve the equation for exact solutions.
We are given to solve:

$4\pi+4\tan^{-1}(x)=\pi$

What do you think should be the first step to solve for x?
• May 2nd 2013, 07:01 PM
ManosG
Re: Solve the equation for exact solutions.
$4\arctan(x) = -3\pi \Leftrightarrow \arctan(x) = \frac{-3\pi}{4} \Leftrightarrow x = \tan(\frac{-3\pi}{4}) = 1$
• May 3rd 2013, 12:40 AM
MarkFL
Re: Solve the equation for exact solutions.
Quote:

Originally Posted by ManosG
$4\arctan(x) = -3\pi \Leftrightarrow \arctan(x) = \frac{-3\pi}{4} \Leftrightarrow x = \tan(\frac{-3\pi}{4}) = 1$

What about $-\frac{\pi}{2}<\tan^{-1}(x)<\frac{\pi}{2}$ ?

Also, on math help sites, it is common courtesy to not give solutions or further hints after someone has tried to engage the OP to work the problem for themselves. When you do this, you devalue the help trying to be judiciously given.