In triangle \(PQR\), we have \(\angle P = 90^\circ\), \(QR = 15\), and \(\tan R = 5\cos Q\). What is \(PQ\)?
Here is one way:
tanr = sinr /cos r = 5 cos q
sin r = cos r 5 cos q
pq/15 = pr/15 5 pq/15
1 = 5 pr/15
3 = pr use pythag theorem to find pq = sqrt 216