If cotA= 15/8 find the value of tan2A.

= cotA = \(\frac{15}{8}\)

= tanA = \(\frac{8}{15}\)

Put in → tan2A=\(\frac{2tanA}{1-tan^2A}\)

⇒\(\frac{2×\frac{8}{15}}{1-\frac{64}{225}}\) =\(\frac{16}{15}\)×\(\frac{225}{161}\)

= \(\frac{240}{161}\)