Limit as x approaches 0 of (tan7x)/(sin3x)

How can you find the mean absolute deviation (mad) for this set of data?

If t8 = 4 and t12 = −2, find the first three terms of the arithmetic sequence.

In triangle abc, angle c is a right angle. find the value of the trig function indicated. find tan a if c = 17 and a = 8