Question

Find tan2θ if θ terminates in Quadrant IV and cosθ =3/5 .

Answer 1

Answer:

The answer to your question is  $\frac{-8}{3}$

Step-by-step explanation:

Data

cos Ф = 3/5

tan2Ф = ?

Quadrant IV

Process

1.- Remember that tanФ = $\frac{Opposite side}{Adjacent side}$  and cos Ф = $\frac{adjacent side}{hypotenuse}$

then,    adjacent side = 3 and hypotenuse = 5

2.- Calculate opposite side

             O² = h² - a²

             O² = 5² - 3²

             O² = 25 - 9

              O² = 16

              O = 4

3.- Calculate the tan 2Ф

            tan 2Ф = 2($\frac{-4}{3}$)       The opposite side is negative in the fourth

                                           quadrangle

            tan 2Ф = $\frac{-8}{3}$