1. ## graph transformation

hi,
$\displaystyle y=tan(\theta-45^\circ)$

in solutions it states it meets y-axis at -1
my question about this is how do i know that graph meets the y axis exactly at -1 ?

2. ## Re: graph transformation

at the $y$ axis $\theta = 0$

$\tan(0-45^\circ) = \tan(-45^\circ) = -1$

3. ## Re: graph transformation

Your two axes are the $y$-axis and the $\theta$-axis. If you want to know when the graph meets one axis, set the variable for the other axis to zero. This gives $y = \tan (-45^\circ ) = -1$.