Originally Posted by

**scorpion007** This is the question from memory, i may have potentially made a mistake, but i do believe it is correct. This should all be done without a calculator.

For the equation $\displaystyle y = \arctan(x-1) - a\tan(\frac{\pi}{8})$, find the minimum value for 'a' where y > 0 for all of x. Leave in exact answer form.

Note, on a previous question i was asked to show (without a calculator) that $\displaystyle \tan(\frac{\pi}{8}) = \sqrt{2} - 1$, so that may be relevant.

In fact, i would appreciate if you could explain the second question too.

Thanks