73a. Look at magic triangle in the answer block at left. Write the
formula when r is the unknown quantity.
Now, assume that y has become the unknown quantity.
Given the value of y and r, isolate the unknown. Write the
73b. y = sin x r
formula in the space below.
74a. Write the function formula for tan .
Now, place the formula in a magic triangle.
Look at your magic triangle. Isolate x; write the formula here.
Isolate the unknown when tan and x are given.