Trigonometry

from the equation tan²2X=3/2 how do I find tanX
Thanks

You have to use the double angle identity for tan(2x)

You have to use the double angle identity for tan(2x)

sorry, I don't understand

The identity is:

$tan(A \pm B) = \dfrac{tanA \pm tanB}{1 \mp tanAtanB}$

In your case, A = B

ok, thanks

square root both sides

use the identity for tan2x

http://www.uhigh.ilstu.edu/math/sondgeroth/coll%20alg/09%20col%20alg%20notes%20072%20trig%20identities%20pt%202.htm

In all honesty I'm trying to a trig equation question (question 7b, aqa, pure core 2, 2014) and I'm just perplexed as to how to get the values of X.

Is this a different question? If so, can you post a screenshot?

square root then find the solutions using your preferred method such as the graph but remember to double your range as its tan2x. e.g if it was 0<x<360 make it 0<2x<720 then find values of x by halfing all the angles in the range. note if you divide by two first then find angles between 0 and 360 then you will lose solutions.

This is the correct method, for C2 anyway.

But don't forget, x is going to be - root(3/2) as well as +

I'm only in L6 but i hear it gets a bit more complex next year

Here, the answer and the question

square root then find the solutions using your preferred method such as the graph but remember to double your range as its tan2x. e.g if it was 0<x<360 make it 0<2x<720 then find values of x by halfing all the angles in the range. note if you divide by two first then find angles between 0 and 360 then you will lose solutions.