Question

Find tan2θ if tanθ = -1/2


-4/3
-1
-4/5
-3/4

Answer 1

@Tommynaiter

Answer 2

i have no idea how to do any of it

Answer 3

do you know sum and difference identities ?

Answer 4

I mean double angle formulas ?

Answer 5

nope i wasnt taught any of this and im over half way done with the course

Answer 6

according to double angle formulas \[\large\rm \tan(2 \theta)=\frac{2 \tan \theta}{1-\tan^2 \theta}\]

Answer 7

here is good link with all identities
http://www.analyzemath.com/trigonometry/trigonometric_formulas.html you need to familiar with these in order to do trig :=))

Answer 8

now just use the given information tan theta=-1/2 plug that in

Answer 9

im so confused

Answer 10

find \[\large\rm \tan2θ \]
use the double angle formula
`tan2θ ` can be written as \[\frac{2 \tanθ }{1-\tan^2θ }\]
and since tan theta =-1/2
you can replace all tan with -1/2