the t method confusing (1 Viewer)

[ronaldinho]

could someone explain the "t"-formulae to me.

And why we sometimes let t=tan1/2x and t = tanx

some qns:

3 Use the t = tan1/2x results to simplify:

a) (2tan10) / (1-tan^2 10)

b) (2tan10) / (1+tan^2 10)

c) (2tan2x)/ (1+tan^2 2x)

d)1-tan^2 2x/1+tan^2 2x

Use the t=tan1/2x results to find the exact value of:

a) 2tan15 / 1+tan^2 15

 

[ssglain]

I don't see what the problem is here. x is an arbitrary representation of the angle that you're dealing with. Don't let the x's in the question confuse you. Regardless of what this angle is, you would let t = tan(half the angle) - so in the cases such 3c/d where the angle happens to 2x, t will consequently be tan(x).