Posted by **vidhu** on Thursday, August 9, 2012 at 11:57am.

(sec 8 x - 1)/(sec 4x -1) = tan 8x/tan 4x Prove it!

- trig -
**Reiny**, Thursday, August 9, 2012 at 12:39pm
One of the first things I usually do is test if the identity is true by picking any value of x.

Since it is an identity it should work for all value of x

let x=10

LS = (1/cos80 -1)/(1/cos40-1)

= appr 15.58

RS = tan80/tan40 = appr 6.758

so , not true, no point trying to prove it.

## Answer this Question

## Related Questions

- Integration - Intergrate ¡ì sec^3(x) dx could anybody please check this answer. ...
- calculus (check my work please) - Not sure if it is right, I have check with the...
- calculus - find dy/dx y=ln (secx + tanx) Let u= secx + tan x dy/dx= 1/u * du/dx ...
- Calculus 12th grade (double check my work please) - 2- given the curve is ...
- Math - Prove Trig. Identities 1. sec è (sec è - cos è)= tan^2 è 2. tan^2 è (1 + ...
- calculus - So I am suppose to evaulate this problem y=tan^4(2x) and I am ...
- Trigonometry desperate help, clueless girl here - 2. solve cos 2x-3sin x cos 2x...
- more trig.... how fun!!!! - if you can't help me with my first question hopw you...
- Trigonometry - 1.Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two ...
- Calculus AP - I'm doing trigonometric integrals i wanted to know im doing step ...