Question

Question Below :)

Answer 1

Find tan2theta if theta terminates in Quadrant IV and costheta =4/5

Answer choices are

-24/7
-1/2
1/2
24/7

Answer 2

Trig identities
http://tutorial.math.lamar.edu/pdf/Trig_Cheat_Sheet.pdf


Look at page 2 in the `Double Angle Formulas` section

You should see this identity
\[\Large \tan(2\theta) = \frac{2\tan(\theta)}{1-\tan^2(\theta)}\]

Answer 3

Your first step is to use
\[\Large \cos(\theta) = \frac{4}{5}\]
to find the value of \(\tan(\theta)\). Keep in mind that theta is in Q4, so \(\tan(\theta)\) will be negative. Once you determine \(\tan(\theta)\), you use the identity I posted above

Answer 4

I got -24/7

Answer 5

what did you get for \(\tan(\theta)\)?