Find the exact value of tan 2x if tan x=7/11, and pi\leqx\leq 3pi/2

Question

Find the exact value of tan 2x if tan x=7/11, and pi
`\leq`x
`\leq` 3pi/2

Answer 1

this is the concept of trigonometry, by trigonometric rules:
tan 2x=[2tan x]/[1-tan^2 x]
given that tan x=7/11
then:
tan 2x=[2*7/11]/[1-(7/11)^2]
=[14/11]/[1-49/121]
=[14/11]/[72/121]
=77/36