Answer
True.
The other four trigonometric functions, $tan~x,~cot~x,~sec~x,~csc~x$ can be written as functions of $sin~x$ and $cos~x$.
Work Step by Step
$tan~x=\frac{sin~x}{cos~x}$
$cot~x=\frac{cos~x}{sin~x}$
$sec~x=\frac{1}{cos~x}$
$csc~x=\frac{1}{sin~x}$
