3. Use the cofunction identities to write an expression that is equivalent to each of the following expressions.
Tan 3/8
3(180)/8= 67.5
=cot (/2-67.5)
=cot 22.5 22.5 x /180
= cot /4
the answer is cot /8 I dont know why though..
co-function identities ...
$\displaystyle \sin(x) = \cos\left(\frac{\pi}{2} - x\right)$
$\displaystyle \tan(x) = \cot\left(\frac{\pi}{2} - x\right)$
$\displaystyle \sec(x) = \csc\left(\frac{\pi}{2} - x\right)$
now ... what is $\displaystyle \frac{\pi}{2} - \frac{3\pi}{8}$ ?