Question

If sin A = 4/5 and A is in quadrant II, find tan 2A.​

Answer 1

The value of tan2A given the trig expression is -128/21

Double angles

According to the double angle formula

tan 2A = 2tanA/1-tan²A

Given the following

sinA = 4/5 = opp/hyp

Tangent = 3units

TanA = opp/adj

TanA = 4/3

Substitute

Tan2A = 2(4/3)/1-(4/3)²

Tan2A = (8/3)/1-(16/9)

Tan2A = 8/3 * -16/7

Tan2A = -128/21

Hence the value of tan2A given the trig expression is -128/21

Learn more on double angle here: brainly.com/question/14691

#SPJ1